dt-bindings: arm: amlogic: meson-gx-ao-secure: support more SoCs

Add new compatible for ao-secure of Amlogic SoCs(S6,S7,S7D).

Acked-by: Conor Dooley <[e-mail]>
Signed-off-by: Xianwei Zhao <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Neil Armstrong <[e-mail]>

Documentation/devicetree/bindings/arm/amlogic/amlogic,meson-gx-ao-secure.yaml

···
               - amlogic,a4-ao-secure
               - amlogic,c3-ao-secure
               - amlogic,s4-ao-secure
+              - amlogic,s6-ao-secure
+              - amlogic,s7-ao-secure
+              - amlogic,s7d-ao-secure
               - amlogic,t7-ao-secure
           - const: amlogic,meson-gx-ao-secure
           - const: syscon