ramips: correct the PCIe port number for some mt7621 devices

ramips: correct the PCIe port number for some mt7621 devices

MT7621 uses a new PCIe driver in the 5.15+ kernel. Allocating wrong PCIe
port will cause the PCIe NIC to not work properly. This commit fixes
the wrong port numbers on Netgear R6220, WAC104 and WNDR3700 v5.

According to bootlog, MT7612E (5GHz) is connected to pcie0, and
MT7603E (2GHz) is connected to pcie2:
[2.758986] mt7621-pci 1e140000.pcie: pcie1 no card, disable it (RST & CLK)
[2.772862] mt7621-pci 1e140000.pcie: PCIE0 enabled
[2.782579] mt7621-pci 1e140000.pcie: PCIE2 enabled
...
[3.009151] pci 0000:01:00.0: [14c3:7662] type 00 class 0x028000
[3.125715] pci 0000:02:00.0: [14c3:7603] type 00 class 0x028000

Tested-by: Maximilian Baumgartner <aufhaxer@googlemail.com>
Signed-off-by: Shiji Yang <yangshiji66@qq.com>
[felix.bau@gmx.de: adjust commit message for Netgear devices]
Signed-off-by: Felix Baumann <felix.bau@gmx.de>