kernel: Handle kernel modules correctly

Place kernel module output in the correct location.
Perform depmod steps (copied from build-image-kernel-modules function in
build/make/core/Makefile).
See: https://source.android.com/devices/architecture/kernel/modular-kernels

Change-Id: I6e70012a5c1acdb276f9bee0d57631d2805f71ea
1 file changed