linux/android/configs

The files in this directory are meant to be used as a base for an Android
kernel config. All devices should have the options in android-base.cfg enabled.
While not mandatory, the options in android-recommended.cfg enable advanced
Android features.

Assuming you already have a minimalist defconfig for your device, a possible
way to enable these options would be:

     ARCH=<arch> scripts/kconfig/merge_config.sh <path_to>/<device>_defconfig android/configs/android-base.cfg android/configs/android-recommended.cfg

This will generate a .config that can then be used to save a new defconfig or
compile a new kernel with Android features enabled.