rtlwifi: Eliminate raw reads and writes from PCIe portion

The PCIe driver used raw reads and writes on the PCIe hardware.
As all of these are only affecting the configuration space, all of
then can be converted to pci_{read,write}_config_XX calls.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>