mmc: dt: tmio_mmc: document R8A77980 bindings

Document the R-Car V3H (R8A77980) SoC in the Renesas SDHI bindings.
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>

Documentation/devicetree/bindings/mmc/tmio_mmc.txt

@@ -26,6 +26,7 @@ Required properties:
 		"renesas,sdhi-r8a7794" - SDHI IP on R8A7794 SoC
 		"renesas,sdhi-r8a7795" - SDHI IP on R8A7795 SoC
 		"renesas,sdhi-r8a7796" - SDHI IP on R8A7796 SoC
+		"renesas,sdhi-r8a77980" - SDHI IP on R8A77980 SoC
 		"renesas,sdhi-r8a77995" - SDHI IP on R8A77995 SoC
 		"renesas,sdhi-shmobile" - a generic sh-mobile SDHI controller
 		"renesas,rcar-gen1-sdhi" - a generic R-Car Gen1 SDHI controller