During firmware recovery and ROC (Remain On Channel) abort operations,
the driver iterates over active interfaces and calls MCU functions that
require the device mutex to be held, but the mutex was not acquired.

This causes system-wide hangs where network commands hang indefinitely,
processes get stuck in uninterruptible sleep (D state), and the system
becomes completely unresponsive requiring force reboot.

Add mutex protection around interface iteration in:
- mt7925_mac_reset_work(): Called during firmware recovery after MCU
  timeouts to reconnect all interfaces
- PCI suspend path: Wrap mt7925_roc_abort_sync() call with mutex

Note: The mutex is added at the call site in pci.c rather than inside
mt7925_roc_abort_sync() because this function is also called from the
station remove path which already holds the mutex.

Reported-by: Zac Bowling <zac@zacbowling.com>
Tested-by: Zac Bowling <zac@zacbowling.com>
Signed-off-by: Zac Bowling <zac@zacbowling.com>

…O PM

Two additional code paths iterate over active interfaces and call MCU
functions without proper mutex protection:

1. mt7925_set_runtime_pm(): Called when runtime PM settings change.
   The ieee80211_iterate_active_interfaces() call invokes
   mt7925_pm_interface_iter() which calls mt7925_mcu_set_beacon_filter().

2. mt7925_mlo_pm_work(): Workqueue function for MLO power management.
   The iterator callback mt7925_mlo_pm_iter() calls mt7925_mcu_uni_bss_ps().

Add mutex protection around the iterate calls in both functions. For
mt7925_mlo_pm_iter(), move the mutex from inside the callback to the
caller (mt7925_mlo_pm_work) for consistency with other patterns.

This matches the pattern used in the older mt7615 driver and other
wireless drivers like iwlwifi.

Reported-by: Zac Bowling <zac@zacbowling.com>
Tested-by: Zac Bowling <zac@zacbowling.com>
Signed-off-by: Zac Bowling <zac@zacbowling.com>