Include Kaleidoscope.h in layers.cpp

To make things easier, just include the main header. It includes
everything else we need, and this way we do not need to cherry pick, nor
care if any of the other headers move, disappear, etc.

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>

src/layers.cpp

@@ -1,5 +1,4 @@
-#include "layers.h"
+#include "Kaleidoscope.h"
-#include "key_events.h"
 
 static uint8_t DefaultLayer;
 static uint32_t LayerState;