tegra: p1761: enable OC4 soc_therm HW throttle

tegra: p1761: enable OC4 soc_therm HW throttle

This patch enables OC4 HW throttle for P1761 TN8 platform. INA power
monitor sensor is driving the OC4 soc_therm input to throttle GPU&CPU
when safe battery current limits are exceeded.

For now, the battery OC limit is set to 6450mA

Bug 1339846

Change-Id: I8767adea4ee82226deba2b7ccf72a5f6e8f6115f
Signed-off-by: Timo Alho <talho@nvidia.com>
Reviewed-on: http://git-master/r/352695
Reviewed-by: Steve Rogers <srogers@nvidia.com>
Reviewed-by: Diwakar Tundlam <dtundlam@nvidia.com>