soc/tegra: pmc: Add support for SoC specific AOWAKE offsets

soc/tegra: pmc: Add support for SoC specific AOWAKE offsets

For Tegra264, some of the AOWAKE registers have different register
offsets. Prepare for adding the Tegra264 AOWAKE register by moving the
offsets for the AOWAKE registers that are different for Tegra264 into
the 'tegra_pmc_regs' structure and populate these offsets for the SoCs
that support these registers.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>