wifi: mt76: mt7921: delete stray if statement

This if statement is never true.  It was supposed to have been deleted
as part of commit 454b768f

 ("mt76: mt7921: Let PCI core handle
power state and use pm_sleep_ptr()") but was missed.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>