Add timestamps to position and behavior events (#147)

* Add timestamps to position events and behaviors.

- Take original event timestamps into consideration so nested tap-holds have proper timing.
- Add position and timestamp to keycode state changed event so the one-shot behavior can properly identify other keypresses and timings.
- Add timestamp to position events received from peripheral

* reduce number of arguments to behaviors

app/include/zmk/behavior.h

@@ -10,4 +10,10 @@ struct zmk_behavior_binding {
     char *behavior_dev;
     u32_t param1;
     u32_t param2;
+};
+
+struct zmk_behavior_binding_event {
+    int layer;
+    u32_t position;
+    s64_t timestamp;
 };

app/include/zmk/events/keycode-state-changed.h

@@ -24,6 +24,5 @@ inline struct keycode_state_changed *create_keycode_state_changed(u8_t usage_pag
     ev->usage_page = usage_page;
     ev->keycode = keycode;
     ev->state = state;
-
     return ev;
 }

app/include/zmk/events/position-state-changed.h

@@ -13,6 +13,7 @@ struct position_state_changed {
     struct zmk_event_header header;
     u32_t position;
     bool state;
+    s64_t timestamp;
 };
 
 ZMK_EVENT_DECLARE(position_state_changed);

app/include/zmk/keymap.h

@@ -11,4 +11,4 @@ int zmk_keymap_layer_activate(u8_t layer);
 int zmk_keymap_layer_deactivate(u8_t layer);
 int zmk_keymap_layer_toggle(u8_t layer);
 
-int zmk_keymap_position_state_changed(u32_t position, bool pressed);
+int zmk_keymap_position_state_changed(u32_t position, bool pressed, s64_t timestamp);