arm64: tegra: Allow the PMIC RTC to wakeup Jetson Xavier

The PMIC RTC is currently unable to wakeup Tegra194 on the Jetson Xavier
platform because the interrupt from the PMIC is not usin the PMC as the
interrupt parent but the GIC directly. Update the PMIC interrupt to use
the PMC as the interrupt parent so that the PMIC RTC alarms can wakeup
the device.

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