The interface control register of the 60xx (and later) Marvell chip
requires certain bits to always be set when writing to it.  These bits
incorrectly read-back as zeros, so the pattern must be ORed in
with each write of the register.  Also, bit 12 should NOT be set
(note that Marvell's own driver also had bit-12 wrong here).

While we're at it, we also now do pci_set_master() in the init code.
Signed-off-by: Mark Lord <liml@rtr.ca>
Signed-off-by: Jeff Garzik <jeff@garzik.org>