dt-bindings: clock: renesas: cpg-mssr: Document r8a77961 support

Add DT binding documentation for the Clock Pulse Generator / Module
Standby and Software Reset block in the Renesas R-Car M3-W+ (R8A77961)
SoC.

Update all references to R-Car M3-W from "r8a7796" to "r8a77960", to
avoid confusion between R-Car M3-W (R8A77960) and M3-W+.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20191023122941.12342-2-geert+renesas@glider.be

Documentation/devicetree/bindings/clock/renesas,cpg-mssr.txt

@@ -27,7 +27,8 @@ Required Properties:
       - "renesas,r8a7793-cpg-mssr" for the r8a7793 SoC (R-Car M2-N)
       - "renesas,r8a7794-cpg-mssr" for the r8a7794 SoC (R-Car E2)
       - "renesas,r8a7795-cpg-mssr" for the r8a7795 SoC (R-Car H3)
-      - "renesas,r8a7796-cpg-mssr" for the r8a7796 SoC (R-Car M3-W)
+      - "renesas,r8a7796-cpg-mssr" for the r8a77960 SoC (R-Car M3-W)
+      - "renesas,r8a77961-cpg-mssr" for the r8a77961 SoC (R-Car M3-W+)
       - "renesas,r8a77965-cpg-mssr" for the r8a77965 SoC (R-Car M3-N)
       - "renesas,r8a77970-cpg-mssr" for the r8a77970 SoC (R-Car V3M)
       - "renesas,r8a77980-cpg-mssr" for the r8a77980 SoC (R-Car V3H)
@@ -42,10 +43,10 @@ Required Properties:
   - clock-names: List of external parent clock names. Valid names are:
       - "extal" (r7s9210, r8a7743, r8a7744, r8a7745, r8a77470, r8a774a1,
 		 r8a774b1, r8a774c0, r8a7790, r8a7791, r8a7792, r8a7793,
-		 r8a7794, r8a7795, r8a7796, r8a77965, r8a77970, r8a77980,
-		 r8a77990, r8a77995)
-      - "extalr" (r8a774a1, r8a774b1, r8a7795, r8a7796, r8a77965, r8a77970,
-		  r8a77980)
+		 r8a7794, r8a7795, r8a77960, r8a77961, r8a77965, r8a77970,
+		 r8a77980, r8a77990, r8a77995)
+      - "extalr" (r8a774a1, r8a774b1, r8a7795, r8a77960, r8a77961, r8a77965,
+		  r8a77970, r8a77980)
       - "usb_extal" (r8a7743, r8a7744, r8a7745, r8a77470, r8a7790, r8a7791,
 		     r8a7793, r8a7794)