fs: nls: add missing MODULE_DESCRIPTION() macros

fs: nls: add missing MODULE_DESCRIPTION() macros

Fix the following allmodconfig "make W=1" issues:

WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/mac-celtic.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/mac-centeuro.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/mac-croatian.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/mac-cyrillic.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/mac-gaelic.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/mac-greek.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/mac-iceland.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/mac-inuit.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/mac-romanian.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/mac-roman.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/mac-turkish.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_ascii.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_cp1250.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_cp1251.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_cp1255.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_cp437.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_cp737.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_cp775.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_cp850.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_cp852.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_cp855.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_cp857.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_cp860.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_cp861.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_cp862.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_cp863.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_cp864.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_cp865.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_cp866.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_cp869.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_cp874.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_cp932.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_cp936.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_cp949.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_cp950.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_euc-jp.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_iso8859-13.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_iso8859-14.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_iso8859-15.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_iso8859-1.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_iso8859-2.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_iso8859-3.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_iso8859-4.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_iso8859-5.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_iso8859-6.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_iso8859-7.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_iso8859-9.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_koi8-r.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_koi8-ru.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_koi8-u.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_ucs2_utils.o
WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nls/nls_utf8.o

Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Link: https://lore.kernel.org/r/20240516-md-fs-nls-v1-1-ed540d8239bf@quicinc.com
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>