rt2x00: rt2800lib: fix band selection and LNA PE control for RT3593 PCIe cards

rt2x00: rt2800lib: fix band selection and LNA PE control for RT3593 PCIe cards

The band selection and PE control code for the
RT3593 chipsets only handles USB based devices
currently. Due to this limitation RT3593 based
PCIe cards are not working correctly.

On PCIe cards band selection is controlled via
GPIO #8 which is identical to the USB devices.
The LNA PE control is slightly different, all
LNA PEs are controlled by GPIO #4.

Update the code to configure the GPIO_CTRL register
correctly on PCIe devices.

Cc: Steven Liu <steven.liu@mediatek.com>
Cc: JasonYS Cheng <jasonys.cheng@mediatek.com>
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>