MAINTAINERS: Update the devicetree documentation path of hyperbus

Change the devicetree documentation path
to "Documentation/devicetree/bindings/mtd/ti,am654-hbmc.yaml"
since 'cypress,hyperflash.txt' and 'ti,am654-hbmc.txt' have
been converted to 'ti,am654-hbmc.yaml'.
Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20211014110614.3320-1-caihuoqing@baidu.com

MAINTAINERS

@@ -8707,8 +8707,7 @@ S:	Supported
 Q:	http://patchwork.ozlabs.org/project/linux-mtd/list/
 C:	irc://irc.oftc.net/mtd
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git cfi/next
-F:	Documentation/devicetree/bindings/mtd/cypress,hyperflash.txt
-F:	Documentation/devicetree/bindings/mtd/ti,am654-hbmc.txt
+F:	Documentation/devicetree/bindings/mtd/ti,am654-hbmc.yaml
 F:	drivers/mtd/hyperbus/
 F:	include/linux/mtd/hyperbus.h