rt2x00: rt61pci needs another millisecond after firmware upload

After the hardware has indicated the firmware upload has completed
and the device is ready, we should wait another millisecond to
make sure the device is really ready to continue.

Without this timout, bringing the interface down and up again will
fail due to incorrect register initialization.

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