dt-bindings: mmc: tmio_mmc: document Renesas R8A77970 bindings

Document the R-Car V3M (R8A77970) SoC in the R-Car SDHI bindings -- it's
the usual R-Car gen3 compatible controller with the internal DMA engine.
Signed-off-by: NSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NSimon Horman <horms+renesas@verge.net.au>

Documentation/devicetree/bindings/mmc/tmio_mmc.txt

@@ -28,6 +28,7 @@ Required properties:
 		"renesas,sdhi-r8a7795" - SDHI IP on R8A7795 SoC
 		"renesas,sdhi-r8a7796" - SDHI IP on R8A7796 SoC
 		"renesas,sdhi-r8a77965" - SDHI IP on R8A77965 SoC
+		"renesas,sdhi-r8a77970" - SDHI IP on R8A77970 SoC
 		"renesas,sdhi-r8a77980" - SDHI IP on R8A77980 SoC
 		"renesas,sdhi-r8a77990" - SDHI IP on R8A77990 SoC
 		"renesas,sdhi-r8a77995" - SDHI IP on R8A77995 SoC