Move prebuilt kernel stuff to BoardConfig

Conflicts:
	device.mk

Change-Id: Ied29f1318ddc3412427c67379134c02923abf878
BoardConfig.mk: remove prebuilt kernel

add defconfig for my kernel
rascarlo.dependencies: add kernel repo

Change-Id: Iba9b58f98cf48c494f94e01cef429ecd2b9ea0fc