arm64: tegra: Update Jetson TX1 GPU regulator timings

The GPU regulator enable ramp delay for Jetson TX1 is set to 1ms which
not sufficient because the enable ramp delay has been measured to be
greater than 1ms. Furthermore, the downstream kernels released by NVIDIA
for Jetson TX1 are using a enable ramp delay 2ms and a settling delay of
160us. Update the GPU regulator enable ramp delay for Jetson TX1 to be
2ms and add a settling delay of 160us.

Cc: stable@vger.kernel.org
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Fixes: 5e6b9a89 ("arm64: tegra: Add VDD_GPU regulator to Jetson TX1")
Signed-off-by: Thierry Reding <treding@nvidia.com>