ARM: tegra: PMC DT support

ARM: tegra: PMC DT support

PMC DT support changes are as follows:
 - Downstream code needs local changes in addition
   to upstream PMC DT support change to compile fine.
   Common clock framework (CCF) is not enabled downstream
   today as a result we cannot switch to upstream version
   of the function set_power_timers today.
 - All PMC platform data from board files is not available
   in DT bindings upstream. Using the board passed
   values in such cases to ensure that functionality
   is intact.
 - Further, if DT attribute values do not match
   board platform data settings the board setting
   is used for the time being.

bug 1173104

Change-Id: Ife63ab84178c5aa4371bfee188ce919a99f651fc
Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
Reviewed-on: http://git-master/r/263727