rt2x00: rt2800pci: use separate ops for the SoC driver

This makes it possible to use different callback
functions for PCI and SoC devices which will allow
to move the SoC driver into a separate module.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>