mv some stuff to android_device_oppo_msm8974-common

Change-Id: I5dc0966cb04295929758be9eab3359c62d827cc6

cleanup dependencies

Change-Id: I20a84a22f54718cfc0686662fe083d7d740023a2

add missing system.prop

Change-Id: I2d954df2d8203be657434ccb946426d91b4ff857

more cleanup

Change-Id: Ibda0addcb61774d8c0e23a8a2b56e4dce8248767