ASoC: rsnd: Add device tree support for r8a774[35]

Document r8a774[35] specific compatible strings. The Renesas RZ/G1[ME]
(r8a774[35]) sound modules are identical to the R-Car Gen2 family.
No driver change is needed as the fallback compatible string
"renesas,rcar_sound-gen2" activates the right code in the driver.
Signed-off-by: Biju Das <biju.das@bp.renesas.com>
Reviewed-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/renesas,rsnd.txt

@@ -4,7 +4,7 @@ Renesas R-Car sound
 * Modules
 =============================================
 
-Renesas R-Car sound is constructed from below modules
+Renesas R-Car and RZ/G sound is constructed from below modules
 (for Gen2 or later)
 
  SCU		: Sampling Rate Converter Unit
@@ -334,9 +334,11 @@ Required properties:
 
 - compatible			: "renesas,rcar_sound-<soctype>", fallbacks
 				  "renesas,rcar_sound-gen1" if generation1, and
-				  "renesas,rcar_sound-gen2" if generation2
+				  "renesas,rcar_sound-gen2" if generation2 (or RZ/G1)
 				  "renesas,rcar_sound-gen3" if generation3
 				  Examples with soctypes are:
+				    - "renesas,rcar_sound-r8a7743" (RZ/G1M)
+				    - "renesas,rcar_sound-r8a7745" (RZ/G1E)
 				    - "renesas,rcar_sound-r8a7778" (R-Car M1A)
 				    - "renesas,rcar_sound-r8a7779" (R-Car H1)
 				    - "renesas,rcar_sound-r8a7790" (R-Car H2)