soc/tegra: pmc: Configure deep sleep control settings

soc/tegra: pmc: Configure deep sleep control settings

Tegra210 and prior Tegra chips have deep sleep entry and wakeup related
timings which are platform specific that should be configured before
entering into deep sleep.

Below are the timing specific configurations for deep sleep entry and
wakeup.
- Core rail power-on stabilization timer
- OSC clock stabilization timer after SOC rail power is stabilized.
- Core power off time is the minimum wake delay to keep the system
  in deep sleep state irrespective of any quick wake event.

These values depends on the discharge time of regulators and turn OFF
time of the PMIC to allow the complete system to finish entering into
deep sleep state.

These values vary based on the platform design and are specified
through the device tree.

This patch has implementation to configure these timings which are must
to have for proper deep sleep and wakeup operations.

Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>