Use iftype for interface type switch in mt7925_init_he_caps routine. This found
during code review but later Coverity reported this with id 1549845.

Fixes: c948b5da ("wifi: mt76: mt7925: add Mediatek Wi-Fi7 driver for mt7925 chips")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/7de6e939dc75ee08f05bf1ee73253aa7eeccf28e.1699869649.git.lorenzo@kernel.org