rt2x00: Don't initialize MM40 HT protection to RTS/CTS on PCI devices

rt2x00: Don't initialize MM40 HT protection to RTS/CTS on PCI devices

Since HT protection is now configurable via mac80211 we don't need this
special case for PCI devices anymore. The HT protection config will be
overwritten as soon as mac80211 sends us a HT operation mode. Hence,
bring the HT MM40 protection config in sync with the other HT protection
registers and initialize it to no protection.

Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>