MAINTAINERS: add maintainer entry for FREESCALE QUAD SPI driver

Add a maintainer entry for FREESCALE QUAD SPI driver and add myself as a
maintainer.

Signed-off-by: Han Xu <han.xu@freescale.com>
Acked-by: Huang Shijie <shijie.huang@intel.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

MAINTAINERS

@@ -4028,6 +4028,12 @@ S:	Maintained
 F:	include/linux/platform_data/video-imxfb.h
 F:	drivers/video/fbdev/imxfb.c
 
+FREESCALE QUAD SPI DRIVER
+M:	Han Xu <han.xu@freescale.com>
+L:	linux-mtd@lists.infradead.org
+S:	Maintained
+F:	drivers/mtd/spi-nor/fsl-quadspi.c
+
 FREESCALE SOC FS_ENET DRIVER
 M:	Pantelis Antoniou <pantelis.antoniou@gmail.com>
 M:	Vitaly Bordug <vbordug@ru.mvista.com>