Cleanup if-statements for simple 1/0 register field values.

This also fixes a endian bug in rt2500usb when working
with the PHY_CSR2 initialization. As well as a bug
in the enabling of the LED in rt73usb.
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>