arm/dt: msm8226: add device tree support for 8x26 v2

The top level DTS files need to uniquely identify different versions
of the chip. Split them off for v1 and v2 specific files.

Change-Id: Ia7d58cdc82337124d348945e4b560dc4babf364a
Signed-off-by: Syed Rameez Mustafa <rameezmustafa@codeaurora.org>