ARM: dts: msm: Add GPU clock support for SDM439/SDM429

Add GPU clock support for SDM439 and SDM429 and its
variants. Different variants of SDM439 are supported
with speed bins.

Also update the DDR bandwidth table for new DDR
clock plan.

Change-Id: I6c9fc5457ef515bc4ba57c4a9d720d32858987be
Signed-off-by: Sunil Khatri <sunilkh@codeaurora.org>