mainboard/google/kahlee: Enable backlight on resume

BUG=b:72694972
TEST=Backlight turns on ChromeOS resume

Change-Id: I452e2ea94b508b137cf52301df5d2d1ad5c9ab70
Signed-off-by: Marc Jones <marcj303@gmail.com>
Reviewed-on: https://review.coreboot.org/27488
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martinroth@google.com>

src/mainboard/google/kahlee/variants/baseboard/mainboard.c

@@ -15,6 +15,9 @@
 
 #include <ec/google/chromeec/ec.h>
 #include <baseboard/variants.h>
+#include <gpio.h>
+#include <variant/gpio.h>
+
 
 uint8_t variant_board_sku(void)
 {
@@ -25,3 +28,11 @@ uint8_t variant_board_sku(void)
 
 	return sku;
 }
+
+#if IS_ENABLED(CONFIG_HAVE_ACPI_RESUME)
+void variant_mainboard_suspend_resume(void)
+{
+	/* Enable backlight - GPIO 133 active low */
+	gpio_set(GPIO_133, 0);
+}
+#endif