arm64: dts: rockchip: add cif clk-control pinctrl for rk3399

This enables variant a of the clkout signal for camera applications
and also the cifclkin pinctrl setting.
Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
Tested-by: Sebastian Fricke <sebastian.fricke@posteo.net>
Acked-by: Helen Koike <helen.koike@collabora.com>
Link: https://lore.kernel.org/r/20210210111020.2476369-6-heiko@sntech.deSigned-off-by: Heiko Stuebner <heiko@sntech.de>

arch/arm64/boot/dts/rockchip/rk3399.dtsi

@@ -2107,6 +2107,18 @@ clk_32k: clk-32k {
 			};
 		};
 
+		cif {
+			cif_clkin: cif-clkin {
+				rockchip,pins =
+					<2 RK_PB2 3 &pcfg_pull_none>;
+			};
+
+			cif_clkouta: cif-clkouta {
+				rockchip,pins =
+					<2 RK_PB3 3 &pcfg_pull_none>;
+			};
+		};
+
 		edp {
 			edp_hpd: edp-hpd {
 				rockchip,pins =