feedbackd: Support visual feedback via LEDs

Currently all LED feedbacks are infinite we can improve that
later on by using the 'repeat' attribute of the LED pattern
trigger.

src/fbd-feedback-led.h

@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2020 Purism SPC
+ *
+ * SPDX-License-Identifier: GPL-3.0+
+ */
+#pragma once
+
+#include "fbd-feedback-base.h"
+
+G_BEGIN_DECLS
+
+typedef enum _FbdFeedbackLedColor {
+  FBD_FEEDBACK_LED_COLOR_WHITE = 0,
+  FBD_FEEDBACK_LED_COLOR_RED = 1,
+  FBD_FEEDBACK_LED_COLOR_GREEN = 2,
+  FBD_FEEDBACK_LED_COLOR_BLUE = 3,
+  FBD_FEEDBACK_LED_COLOR_LAST = FBD_FEEDBACK_LED_COLOR_BLUE,
+} FbdFeedbackLedColor;
+
+#define FBD_TYPE_FEEDBACK_LED (fbd_feedback_led_get_type ())
+
+G_DECLARE_FINAL_TYPE (FbdFeedbackLed, fbd_feedback_led, FBD, FEEDBACK_LED, FbdFeedbackBase);
+
+G_END_DECLS