wifi: rtw88: Fix rtw_mac_power_switch() for RTL8814AU

rtw_mac_power_switch() checks bit 8 of REG_SYS_STATUS1 to see if the
chip is powered on. This bit appears to be always on in the RTL8814AU,
so ignore it.

Signed-off-by: Bitterblue Smith <rtl8821cerfe2@gmail.com>
Acked-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/2f0fcffb-3067-4d95-a68c-f2f3a5a47921@gmail.com