arm64: dts: redfin: Enable ULPS during idle PC

Because this is a command mode panel, we can put the DSI lanes into ULPS
(Ultra-Low Power State) during idle PC (power collapse) to save power.
msm_drm enters idle PC after 58 ms of no frame commits by default, so
this won't affect active display usage.

Test: DVT display turns on and works correctly at 60 and 60 Hz
Signed-off-by: Danny Lin <danny@kdrag0n.dev>

Author: kdrag0n

arch/arm64/boot/dts/google/dsi-panel-s6e3hc2-dvt-dsc-1080p-cmd.dtsi

@@ -66,6 +66,7 @@
 
 		qcom,mdss-dsi-t-clk-post = <0x15>;
 		qcom,mdss-dsi-t-clk-pre = <0x12>;
+		qcom,ulps-enabled;
 
 		qcom,mdss-dsi-bl-notifier-ranges = <115 140 167 1023>;