Add userdebug build variant

Change-Id: I99632bef3925b06625a420f0514a8e3ac8e737ff
urushi: device specific part for the new two-stage boot method

Ported from http://review.cyanogenmod.org/#/c/26440/
Author: codeworkx <codeworkx@cyanogenmod.com>
Signed-off-by: Michael Bestas <mikeioannina@gmail.com>

Change-Id: Ic7acbe6dbe5fdf09c9f45e1eed26d89f0495089a
urushi: Fix default cpu clock after changed to 2-stage boot

Change-Id: I97fe3598675e8950ed62dc6351d1a04f8dc6922e
urushi: remove prebuilt kernel

We build kernel from source since long time
Signed-off-by: Michael Bestas <mikeioannina@gmail.com>

Change-Id: I64f8ce0364a18e2d6c81fa14349eee52d438a42a