fpga: tests: add module descriptions

fpga: tests: add module descriptions

Modules without a description now cause a warning:

WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/fpga/tests/fpga-bridge-test.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/fpga/tests/fpga-mgr-test.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/fpga/tests/fpga-region-test.o

Link: https://lkml.kernel.org/r/20250324173242.1501003-4-arnd@kernel.org
Fixes: 6c6c1fc09de3 ("modpost: require a MODULE_DESCRIPTION()")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Hao Wu <hao.wu@intel.com>
Cc: Jeff Johnson <jeff.johnson@oss.qualcomm.com>
Cc: Marco Pagani <marpagan@redhat.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Moritz Fischer <mdf@kernel.org>
Cc: Russ Weight <russ.weight@linux.dev>
Cc: Stehen Rothwell <sfr@canb.auug.org.au>
Cc: Tom Rix <trix@redhat.com>
Cc: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>