mmc: sh_mmcif: Document r8a7793 DT bindings

Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
[geert: Rebased]
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Documentation/devicetree/bindings/mmc/renesas,mmcif.txt

@@ -11,6 +11,7 @@ Required properties:
 	- "renesas,mmcif-r8a7740" for the MMCIF found in r8a7740 SoCs
 	- "renesas,mmcif-r8a7790" for the MMCIF found in r8a7790 SoCs
 	- "renesas,mmcif-r8a7791" for the MMCIF found in r8a7791 SoCs
+	- "renesas,mmcif-r8a7793" for the MMCIF found in r8a7793 SoCs
 	- "renesas,mmcif-r8a7794" for the MMCIF found in r8a7794 SoCs
 
 - clocks: reference to the functional clock