MIPS: Loongson: Lemote-2F: USB: Not Emulate Non-Posted Writes

Without this patch, when copying large amounts of data between the USB
storage devices and the hard disk, the USB device will disconnect
regularly.

Signed-off-by: Hu Hongbing <huhb@lemote.com>
Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: yanh@lemote.com
Cc: huhb@lemote.com
Cc: zhangfx@lemote.com
Patchwork: http://patchwork.linux-mips.org/patch/822/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>