RT539x devices:
(0x1814, 0x5362)
(0x1814, 0x5392)

Taken from ralink driver 2011_0406_RT5390_RT5392_Linux_STA_V2.5.0.3_DPO
Signed-off-by: Xose Vazquez Perez <xose.vazquez@gmail.com>
Acked-by: Gertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>