clk: sunxi: document PRCM clock compatible strings

Document new compatible strings for clock provided by the PRCM
(Power/Reset/Clock Management) unit.
Signed-off-by: NBoris BREZILLON <boris.brezillon@free-electrons.com>
Signed-off-by: NEmilio López <emilio@elopez.com.ar>

Documentation/devicetree/bindings/clock/sunxi.txt

@@ -20,12 +20,15 @@ Required properties:
 	"allwinner,sun5i-a13-ahb-gates-clk" - for the AHB gates on A13
 	"allwinner,sun5i-a10s-ahb-gates-clk" - for the AHB gates on A10s
 	"allwinner,sun7i-a20-ahb-gates-clk" - for the AHB gates on A20
+	"allwinner,sun6i-a31-ar100-clk" - for the AR100 on A31
 	"allwinner,sun6i-a31-ahb1-mux-clk" - for the AHB1 multiplexer on A31
 	"allwinner,sun6i-a31-ahb1-gates-clk" - for the AHB1 gates on A31
 	"allwinner,sun4i-a10-apb0-clk" - for the APB0 clock
+	"allwinner,sun6i-a31-apb0-clk" - for the APB0 clock on A31
 	"allwinner,sun4i-a10-apb0-gates-clk" - for the APB0 gates on A10
 	"allwinner,sun5i-a13-apb0-gates-clk" - for the APB0 gates on A13
 	"allwinner,sun5i-a10s-apb0-gates-clk" - for the APB0 gates on A10s
+	"allwinner,sun6i-a31-apb0-gates-clk" - for the APB0 gates on A31
 	"allwinner,sun7i-a20-apb0-gates-clk" - for the APB0 gates on A20
 	"allwinner,sun4i-a10-apb1-clk" - for the APB1 clock
 	"allwinner,sun4i-a10-apb1-mux-clk" - for the APB1 clock muxing