Add support to vendor tree with different name

Change-Id: I3dd80563bd0f92b2c25dc39697357e92f21976c7
Move display density definition to device

Change-Id: Ia8fa65583be02fde86b4b78a62871ea513582d3d
Add XT907 to ota-assert

Change-Id: Ic9f0c9511224ff53bbefc38b560841493add5fa9
Move all the proprietaries to vendor tree of each device

Change-Id: I01be08fc41eddbff5e5bab413ad5475bd8f9f4bd