ARM: dts: msm: Reading MDP offsets from device tree for PP functions.

The register address offset values are currently stored in macro
variables. These are now being moved to device tree. These addresses
cannot be calculated in cases of targets which have single DSPP like
8226.

The required register address offset values are added to the
respective target device tree files. The address validation
functions corresponding to PP are modified to read the values from
these newly added device tree entries.

8x10 target does not require this change as it uses MDP3
architecture.

Change-Id: I9387c8fadc36e3bbaceb51b243d3a9537250a3be
Signed-off-by: Krishna Chaitanya Parimi <cparimi@codeaurora.org>