spi: dt-bindings: amlogic, meson-gx-spicc: add Amlogic G12A compatible

The Amlogic G12A SPICC controllers uses a secondary clock used to feed the
baud rate generator and the delay control logic.
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lore.kernel.org/r/20200312133131.26430-9-narmstrong@baylibre.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/spi/amlogic,meson-gx-spicc.yaml

@@ -22,6 +22,7 @@ properties:
     enum:
       - amlogic,meson-gx-spicc # SPICC controller on Amlogic GX and compatible SoCs
       - amlogic,meson-axg-spicc # SPICC controller on Amlogic AXG and compatible SoCs
+      - amlogic,meson-g12a-spicc # SPICC controller on Amlogic G12A and compatible SoCs
 
   interrupts:
     maxItems: 1
@@ -40,6 +41,27 @@ properties:
     items:
       - const: core
 
+if:
+  properties:
+    compatible:
+      contains:
+        enum:
+          - amlogic,meson-g12a-spicc
+
+then:
+  properties:
+    clocks:
+      contains:
+        items:
+          - description: controller register bus clock
+          - description: baud rate generator and delay control clock
+
+    clock-names:
+      minItems: 2
+      items:
+        - const: core
+        - const: pclk
+
 required:
   - compatible
   - reg