arm64: allwinner: a64: Add PLL_PERIPH0 clock to the R_CCU

The AR100 clock within the R_CCU (PRCM) has the PLL_PERIPH0 as one of
its parents.

This adds the reference in the device tree describing this relationship.
This patch uses a raw number for the clock index to ease merging by
avoiding cross tree dependencies.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi

@@ -406,8 +406,9 @@ rtc: rtc@1f00000 {
 		r_ccu: clock@1f01400 {
 			compatible = "allwinner,sun50i-a64-r-ccu";
 			reg = <0x01f01400 0x100>;
-			clocks = <&osc24M>, <&osc32k>, <&iosc>;
-			clock-names = "hosc", "losc", "iosc";
+			clocks = <&osc24M>, <&osc32k>, <&iosc>,
+				 <&ccu 11>;
+			clock-names = "hosc", "losc", "iosc", "pll-periph";
 			#clock-cells = <1>;
 			#reset-cells = <1>;
 		};