wifi: rtw88: Add common USB chip support

Add the common bits and pieces to add USB support to the RTW88 driver.
This is based on https://github.com/ulli-kroll/rtw88-usb.git which
itself is first written by Neo Jou.

Signed-off-by: neo_jou <neo_jou@realtek.com>
Signed-off-by: Hans Ulli Kroll <linux@ulli-kroll.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20221202081224.2779981-8-s.hauer@pengutronix.de