ARM: tegra: cpu: enable VDD_CPU rail before LP to G transition

When doing LP to G transition, it had a power up latency on VDD_CPU
rail. To reduce the latency, CPU_LP can trun on the VDD_CPU rail
before the LP to G transition.

Bug 930985

Change-Id: I087e185ea5aa90f309b8cafba9bc4bb7d3fc950c
Signed-off-by: Joseph Lo <josephl@nvidia.com>
Reviewed-on: http://git-master/r/93141
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Antti Miettinen <amiettinen@nvidia.com>
Tested-by: Antti Miettinen <amiettinen@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Juha Tukkinen <jtukkinen@nvidia.com>

Conflicts:

	arch/arm/mach-tegra/pm.c