rt2x00: Move Move pci_dev specific access to rt2x00pci

pci_dev->irq and pci_name(pci_dev) access should be limited
to rt2x00pci only. This is more generic and allows a rt2x00 pci
driver to be controlled as PCI device but also as platform driver
(needed for rt2800pci SoC support).

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>