C10: enable idle timer with kernel support

Bug: 208375625
Test: perfetto, check pane_idle
Change-Id: I3b23d831fd071cb52f80775fd6468e3006ca166d

conf/init.cheetah.rc

@@ -95,3 +95,11 @@ on property:ro.boot.cdt_hwid=0x00030303000100000200000000000000
 # SecureElement eSE2 cts mode
 on property:persist.vendor.se.ese2.mode=ctsmode
     write /sys/class/st33spi/st33spi/st33spi_state 33
+
+# Display
+on property:graphics.display.kernel_idle_timer.enabled=true
+    # Enable aggressive idle mode switching
+    write /sys/devices/platform/exynos-drm/primary-panel/panel_idle "1"
+
+on property:graphics.display.kernel_idle_timer.enabled=false
+    write /sys/devices/platform/exynos-drm/primary-panel/panel_idle "0"

device-cheetah.mk

@@ -33,6 +33,8 @@ include device/google/gs201/uwb/uwb.mk
 $(call soong_config_set,lyric,tuning_product,cheetah)
 $(call soong_config_set,google3a_config,target_device,cheetah)
 
+PRODUCT_DEFAULT_PROPERTY_OVERRIDES += ro.surface_flinger.support_kernel_idle_timer=true
+
 # Init files
 PRODUCT_COPY_FILES += \
 	device/google/pantah/conf/init.cheetah.rc:$(TARGET_COPY_OUT_VENDOR)/etc/init/hw/init.cheetah.rc