Uses device_phone.mk instead of device.mk

Needs patch in device/sony/lagan

Change-Id: Idde95800cc32e9e65eebab2b03eba8195bfb4333
Cleanup of how we make the device mk files

Less duplication = less chance of bugs

Change-Id: I50fc67878e6e1ae8851dafc548a5d0d8bdc76e7b