kernel: kmod-input-gpio-keys-polled depends on kmod-input-core

kernel: kmod-input-gpio-keys-polled depends on kmod-input-core

While kmod-input-core was previously indirectly selected by
kmod-input-polldev, this is now only the case on Linux 5.10.
Select kmod-input-core as dependency independently of the kernel
version to fix build error:

Package kmod-input-gpio-keys-polled is missing dependencies for the following libraries:
input-core.ko

Fixes: 54878fbbdd ("kernel: kmod-input-polldev: Depend on kernel 5.10")
Signed-off-by: Daniel Golle <daniel@makrotopia.org>