pinctrl: add missing MODULE_DESCRIPTION() macros

pinctrl: add missing MODULE_DESCRIPTION() macros

When ARCH=x86, make allmodconfig && make W=1 C=1 reports:
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/pinctrl/bcm/pinctrl-bcm4908.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/pinctrl/pinctrl-mcp23s08_i2c.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/pinctrl/pinctrl-mcp23s08_spi.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/pinctrl/pinctrl-mcp23s08.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/pinctrl/meson/pinctrl-meson.o

Add the missing invocation of the MODULE_DESCRIPTION() macro to all
files which have a MODULE_LICENSE().

This includes many meson drivers which, although they did not produce
a warning with the x86 allmodconfig configuration, may cause this
warning with ARM or ARM64 configurations.

Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org> # for Amlogic Pinctrl drivers
Link: https://lore.kernel.org/r/20240610-md-drivers-pinctrl-v1-1-68462e3d960c@quicinc.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>