kernel: fix packaging of kmod-gpio-nxp-74hc164

kernel: fix packaging of kmod-gpio-nxp-74hc164

The NXP 74HC164 GPIO expander driver uses a different config symbol
("CONFIG_GPIO_74X164") and module name since since at least Kernel
version 2.6.37.

Update the kmod package definition accordingly by adjusting kconfig
and module file names.

This unrelated, but correct change has been separated from the
WNR2000v5 support commits.

Ref: https://github.com/lede-project/source/pull/1256
Suggested-by: Raphael Catolino <raphael.catolino@gmail.com>
Signed-off-by: Jo-Philipp Wich <jo@mein.io>