iio: adc: Fix Renesas GyroADC MAINTAINERS entry

Fix the F: entry in MAINTAINERS file, point it to the correct file.
While at it, add DT binding doc F: entry too.
Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: linux-renesas-soc@vger.kernel.org
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

MAINTAINERS

@@ -12390,7 +12390,8 @@ RENESAS R-CAR GYROADC DRIVER
 M:	Marek Vasut <marek.vasut@gmail.com>
 L:	linux-iio@vger.kernel.org
 S:	Supported
-F:	drivers/iio/adc/rcar_gyro_adc.c
+F:	Documentation/devicetree/bindings/iio/adc/renesas,gyroadc.txt
+F:	drivers/iio/adc/rcar-gyroadc.c
 
 RENESAS R-CAR I2C DRIVERS
 M:	Wolfram Sang <wsa+renesas@sang-engineering.com>