MAINTAINERS: fix broken doc refs due to yaml conversion

Several *.txt files got converted to yaml. Update their
references at MAINTAINERS file accordingly.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/3b58afec5195d4ea505ea9b3f74d53f7abed4e6f.1603791716.git.mchehab+huawei@kernel.orgSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/devicetree/bindings/clock/hi6220-clock.txt

@@ -4,7 +4,7 @@ Clock control registers reside in different Hi6220 system controllers,
 please refer the following document to know more about the binding rules
 for these system controllers:
 
-Documentation/devicetree/bindings/arm/hisilicon/hisilicon.txt
+Documentation/devicetree/bindings/arm/hisilicon/hisilicon.yaml
 
 Required Properties:
 

MAINTAINERS

@@ -978,7 +978,7 @@ M:	Michael Hennerich <Michael.Hennerich@analog.com>
 L:	linux-iio@vger.kernel.org
 S:	Supported
 W:	http://ez.analog.com/community/linux-device-drivers
-F:	Documentation/devicetree/bindings/iio/adc/adi,ad7768-1.txt
+F:	Documentation/devicetree/bindings/iio/adc/adi,ad7768-1.yaml
 F:	drivers/iio/adc/ad7768-1.c
 
 ANALOG DEVICES INC AD7780 DRIVER
@@ -3860,7 +3860,7 @@ M:	Roger Quadros <rogerq@ti.com>
 L:	linux-usb@vger.kernel.org
 S:	Maintained
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/peter.chen/usb.git
-F:	Documentation/devicetree/bindings/usb/cdns-usb3.txt
+F:	Documentation/devicetree/bindings/usb/cdns,usb3.yaml
 F:	drivers/usb/cdns3/
 
 CADET FM/AM RADIO RECEIVER DRIVER
@@ -7920,7 +7920,7 @@ HISILICON LPC BUS DRIVER
 M:	john.garry@huawei.com
 S:	Maintained
 W:	http://www.hisilicon.com
-F:	Documentation/devicetree/bindings/arm/hisilicon/hisilicon-low-pin-count.txt
+F:	Documentation/devicetree/bindings/arm/hisilicon/low-pin-count.yaml
 F:	drivers/bus/hisi_lpc.c
 
 HISILICON NETWORK SUBSYSTEM 3 DRIVER (HNS3)
@@ -14902,7 +14902,6 @@ RENESAS ETHERNET DRIVERS
 R:	Sergei Shtylyov <sergei.shtylyov@gmail.com>
 L:	netdev@vger.kernel.org
 L:	linux-renesas-soc@vger.kernel.org
-F:	Documentation/devicetree/bindings/net/renesas,*.txt
 F:	Documentation/devicetree/bindings/net/renesas,*.yaml
 F:	drivers/net/ethernet/renesas/
 F:	include/linux/sh_eth.h
@@ -18106,7 +18105,7 @@ M:	Yu Chen <chenyu56@huawei.com>
 M:	Binghui Wang <wangbinghui@hisilicon.com>
 L:	linux-usb@vger.kernel.org
 S:	Maintained
-F:	Documentation/devicetree/bindings/phy/phy-hi3660-usb3.txt
+F:	Documentation/devicetree/bindings/phy/hisilicon,hi3660-usb3.yaml
 F:	drivers/phy/hisilicon/phy-hi3660-usb3.c
 
 USB ISP116X DRIVER

drivers/staging/wfx/Documentation/devicetree/bindings/net/wireless/silabs,wfx.yaml

@@ -24,7 +24,7 @@ description:
     In addition, it is recommended to declare a mmc-pwrseq on SDIO host above
     WFx. Without it, you may encounter issues with warm boot. The mmc-pwrseq
     should be compatible with mmc-pwrseq-simple. Please consult
-    Documentation/devicetree/bindings/mmc/mmc-pwrseq-simple.txt for more
+    Documentation/devicetree/bindings/mmc/mmc-pwrseq-simple.yaml for more
     information.
 
   For SPI':'