power: regulator: Consistently return -ENOSYS when ops is unimplemented

dev_get_driver_ops() may return NULL when the udevice is invalid.

Move the ops check to top of functions to consistently return -ENOSYS
when ops is unimplemented and prevent trying to access uclass plat data,
also add missing NULL checks to suspend ops.

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
1 file changed