dt-bindings: timer: renesas,tmu: Add R-Mobile APE6 support

Document support for the Timer Unit (TMU) on the R-Mobile APE6 (R8A73A4)
Soc.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/17e3fd5f27ab540c8611545ad3dc5a697ca66c58.1716985096.git.geert+renesas@glider.be
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Author: geertu

Documentation/devicetree/bindings/timer/renesas,tmu.yaml

@@ -21,6 +21,7 @@ properties:
   compatible:
     items:
       - enum:
+          - renesas,tmu-r8a73a4  # R-Mobile APE6
           - renesas,tmu-r8a7740  # R-Mobile A1
           - renesas,tmu-r8a774a1 # RZ/G2M
           - renesas,tmu-r8a774b1 # RZ/G2N
@@ -94,6 +95,7 @@ if:
       compatible:
         contains:
           enum:
+            - renesas,tmu-r8a73a4
             - renesas,tmu-r8a7740
             - renesas,tmu-r8a7778
             - renesas,tmu-r8a7779