dt-bindings: zx296718-clk: add compatible for audio clock controller

It adds the compatible string for zx296718 audio clock controller.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

Documentation/devicetree/bindings/clock/zx296718-clk.txt

@@ -13,6 +13,9 @@ Required properties:
 	"zte,zx296718-lsp1crm":
 		zx296718 device level clock selection and gating
 
+	"zte,zx296718-audiocrm":
+		zx296718 audio clock selection, divider and gating
+
 - reg: Address and length of the register set
 
 The clock consumer should specify the desired clock by having the clock