mmc: sh_mmcif: Document r7s72100 DT bindings

Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

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

@@ -8,6 +8,7 @@ Required properties:
 
 - compatible: should be "renesas,mmcif-<soctype>", "renesas,sh-mmcif" as a
   fallback. Examples with <soctype> are:
+	- "renesas,mmcif-r7s72100" for the MMCIF found in r7s72100 SoCs
 	- "renesas,mmcif-r8a73a4" for the MMCIF found in r8a73a4 SoCs
 	- "renesas,mmcif-r8a7740" for the MMCIF found in r8a7740 SoCs
 	- "renesas,mmcif-r8a7778" for the MMCIF found in r8a7778 SoCs
@@ -17,6 +18,13 @@ Required properties:
 	- "renesas,mmcif-r8a7794" for the MMCIF found in r8a7794 SoCs
 	- "renesas,mmcif-sh73a0" for the MMCIF found in sh73a0 SoCs
 
+- interrupts: Some SoCs have only 1 shared interrupt, while others have either
+  2 or 3 individual interrupts (error, int, card detect). Below is the number
+  of interrupts for each SoC:
+    1: r8a73a4, r8a7778, r8a7790, r8a7791, r8a7793, r8a7794
+    2: r8a7740, sh73a0
+    3: r7s72100
+
 - clocks: reference to the functional clock
 
 - dmas: reference to the DMA channels, one per channel name listed in the