wifi: mt76: mt7996: drop always true condition of __mt7996_reg_addr()

addr <= MT_CBTOP2_PHY_END(0xffffffff) is always true (<= u32max),
so drop it.

Fixes: 98686cd2 ("wifi: mt76: mt7996: add driver for MediaTek Wi-Fi 7 (802.11be) devices")
Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>