Convert 'struct pci_dev' to 'struct device' to make it usable on the AHB
bus as well.

Changes-licensed-under: ISC
Signed-off-by: NGabor Juhos <juhosg@openwrt.org>
Signed-off-by: NImre Kaloz <kaloz@openwrt.org>
Tested-by: NPavel Roskin <proski@gnu.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>