ti: k3: common: Add basic PSCI core off support
ti: k3: common: Add basic PSCI core off support

Use TI-SCI messages to request core power down from system controller
firmware.

Signed-off-by: Andrew F. Davis <a6dfde0ec5c5124d26ab0cb4f9ab9a758dee1d6f@ti.com>

achingupta/arm-trusted-firmware,achingupta/arm-trusted-firmware