rt2x00: Identify ASUS USB-N53 device.

commit 177ef8360fabdc49ff08d2598c06e7f7a36b53e3 upstream.

This is an RT3572 based device.

Signed-off-by: Maximilian Engelhardt <maxi@daemonizer.de>
Signed-off-by: Gertjan van Wingerde <gwingerde@gmail.com>
Acked-by: Ivo Van Doorn <ivdoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>