wifi: rtw88: sdio: use indirect IO for device registers before power-on

wifi: rtw88: sdio: use indirect IO for device registers before power-on

The register REG_SYS_CFG1 is used to determine chip basic information
as arguments of following flows, such as download firmware and load PHY
parameters, so driver read the value early (before power-on).

However, the direct IO is disallowed before power-on, or it causes wrong
values, which driver recognizes a chip as a wrong type RF_1T1R, but
actually RF_2T2R, causing driver warns:

  rtw88_8822cs mmc1:0001:1: unsupported rf path (1)

Fix it by using indirect IO before power-on.

Reported-by: Piotr Oniszczuk <piotr.oniszczuk@gmail.com>
Closes: https://lore.kernel.org/linux-wireless/699C22B4-A3E3-4206-97D0-22AB3348EBF6@gmail.com/T/#t
Suggested-by: Bitterblue Smith <rtl8821cerfe2@gmail.com>
Tested-by: Piotr Oniszczuk <piotr.oniszczuk@gmail.com>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/20250724004815.7043-1-pkshih@realtek.com