MAINTAINERS: Update SPI NOR subsystem git repositories

SPI NOR branches are now hosted on MTD repos, spi-nor/next is on l2-mtd
and spi-nor/fixes is on linux-mtd.

Signed-off-by: Cyrille Pitchen <cyrille.pitchen@wedev4u.fr>
Acked-by: Marek Vasut <marek.vasut@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

MAINTAINERS

@@ -12122,7 +12122,8 @@ M:	Marek Vasut <marek.vasut@gmail.com>
 L:	linux-mtd@lists.infradead.org
 W:	http://www.linux-mtd.infradead.org/
 Q:	http://patchwork.ozlabs.org/project/linux-mtd/list/
-T:	git git://github.com/spi-nor/linux.git
+T:	git git://git.infradead.org/linux-mtd.git spi-nor/fixes
+T:	git git://git.infradead.org/l2-mtd.git spi-nor/next
 S:	Maintained
 F:	drivers/mtd/spi-nor/
 F:	include/linux/mtd/spi-nor.h