mt: mt7921: Add AP mode support

mt: mt7921: Add AP mode support

add AP mode support to mt7921 that can work for mt7921[e,s,u]
with the common code.

Original Commit
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/net/wireless/mediatek/mt76/mt7921?h=v6.8-rc5&id=116c69603b01f2d6e4499ca5d535f5b71c52052c

Original Author: Sean Wang <sean.wang@mediatek.com>
Tested-by: Deren Wu <deren.wu@mediatek.com>
Tested-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Tested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Change-Id: Ib3ac17cb24bcc219166661430335f274d1c2f3a5
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Reported-by: Seonah Moon <seonah1.moon@samsung.com>