ANDROID: TI: build: add build.config.ti

This is the build configuration to be used with the Android Common Kernel build scripts as documented here:

https://source.android.com/setup/build/building-kernels

Steps are here: https://baylibre.gitlab.io/ti/android/doc/getting-started.html#fetching-the-kernel-code

Note: We use the merge_configs script for merging fragments.

Task: TIA-31

Signed-off-by: Imen BEN HASSEN ibenhassen@baylibre.com