dt-bindings: timer: renesas: cmt: document R-Car gen3 support

Document support for the R-Car gen3 CMT types 0/1 bindings -- they seem
to be the same CMT types 0/1 as in the R-Car gen2 SoCs.

Also document R8A779{7|8}0 bindings as these are the R-Car gen3 SoCs for
which the initial support was done.

Signed-off-by: Sergei Shtylyov <[e-mail]>
Reviewed-by: Geert Uytterhoeven <[e-mail]>
Signed-off-by: Daniel Lezcano <[e-mail]>

Documentation/devicetree/bindings/timer/renesas,cmt.txt

···
     - "renesas,r8a7793-cmt1" for the 48-bit CMT1 device included in r8a7793.
     - "renesas,r8a7794-cmt0" for the 32-bit CMT0 device included in r8a7794.
     - "renesas,r8a7794-cmt1" for the 48-bit CMT1 device included in r8a7794.
+    - "renesas,r8a77970-cmt0" for the 32-bit CMT0 device included in r8a77970.
+    - "renesas,r8a77970-cmt1" for the 48-bit CMT1 device included in r8a77970.
+    - "renesas,r8a77980-cmt0" for the 32-bit CMT0 device included in r8a77980.
+    - "renesas,r8a77980-cmt1" for the 48-bit CMT1 device included in r8a77980.
 
     - "renesas,rcar-gen2-cmt0" for 32-bit CMT0 devices included in R-Car Gen2
 		and RZ/G1.
···
 		and RZ/G1.
 		These are fallbacks for r8a73a4, R-Car Gen2 and RZ/G1 entries
 		listed above.
+    - "renesas,rcar-gen3-cmt0" for 32-bit CMT0 devices included in R-Car Gen3.
+    - "renesas,rcar-gen3-cmt1" for 48-bit CMT1 devices included in R-Car Gen3.
+		These are fallbacks for R-Car Gen3 entries listed above.
 
   - reg: base address and length of the registers block for the timer module.
   - interrupts: interrupt-specifier for the timer, one per channel.