soc: add missing MODULE_DESCRIPTION() macros

With ARCH=x86, make allmodconfig && make W=1 C=1 reports:
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/soc/imx/soc-imx8m.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/soc/ixp4xx/ixp4xx-qmgr.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/soc/ixp4xx/ixp4xx-npe.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/soc/mediatek/mtk-cmdq-helper.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/soc/amlogic/meson-clk-measure.o

Add the missing invocations of the MODULE_DESCRIPTION() macro.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Shawn Guo <shawnguo@kernel.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org> # for amlogic/meson-clk-measure.c
Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Link: https://lore.kernel.org/r/20240625-md-drivers-soc-v2-1-8bc7c03e3e69@quicinc.com


Signed-off-by: Arnd Bergmann <arnd@arndb.de>