[PATCH] arm64: dts: rockchip: Add 32k clk on rk3399-gru

[Derek Basehore <dbasehore@chromium.org>]

This adds the 32k clock to the RK3399 Gru board file. Even though it's
not directly used, muxes will end up traversing the entire clk tree on
calls to determine_rate if it doesn't exist. This is because the 32k
clk is listed as a possible parent on some clks. Since the clk doesn't
know about the 32k clk (it was never registered), it triggers a global
search for it. This can happen about 40 times per second, which isn't
great for power.

Signed-off-by: Derek Basehore <dbasehore@chromium.org>
---
 arch/arm64/boot/dts/rockchip/rk3399-gru.dtsi | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/arm64/boot/dts/rockchip/rk3399-gru.dtsi b/arch/arm64/boot/dts/rockchip/rk3399-gru.dtsi
index ca07f6032200..a07aa4c570c0 100644
--- a/arch/arm64/boot/dts/rockchip/rk3399-gru.dtsi
+++ b/arch/arm64/boot/dts/rockchip/rk3399-gru.dtsi
@@ -14,6 +14,13 @@
 		stdout-path = "serial2:115200n8";
 	};
 
+	ap_rtc_clk: ap-rtc-clk {
+		compatible = "fixed-clock";
+		clock-frequency = <32768>;
+		clock-output-names = "xin32k";
+		#clock-cells = <0>;
+	};
+
 	/*
 	 * Power Tree
 	 *
-- 
2.20.0.rc0.387.gc7a69e6b6c-goog