soc: apple: apple-pmgr-pwrstate: Switch to IRQ-safe mode

This requires changing the reset path locking primitives to the spinlock
path in genpd, instead of the mutex path.

Reviewed-by: Eric Curtin <ecurtin@redhat.com>
Reviewed-by: Sven Peter <sven@svenpeter.dev>
Signed-off-by: Hector Martin <marcan@marcan.st>