feat(psci): require validate_power_state to expose CPU_SUSPEND

psci_cpu_suspend unconditionally calls psci_validate_power_state, which
asserts that the platform implements ops->validate_power_state. To avoid
a failure at runtime, do not expose CPU_SUSPEND unless that callback is
implemented. This also allows a platform to provide SYSTEM_SUSPEND
without providing CPU_SUSPEND.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Change-Id: I5dafb7845f482ab3af03a9de562def41dd70189e
1 file changed