ARM: dts: msm: Add initial device tree for pm7250b

Add initial device tree for pm7250b and base nodes for revid,
pon, charger, qgauge, gpio and temp alarm peripherals.

Change-Id: I4560383f55cf6951a2336f284ffa981e2544c048
Signed-off-by: Umang Agrawal <uagrawal@codeaurora.org>