Add REGA Alarm call functionality

ui/ui.c

@@ -30,6 +30,9 @@
 #ifdef ENABLE_FMRADIO
     #include "ui/fmradio.h"
 #endif
+#ifdef ENABLE_REGA
+    #include "app/rega.h"
+#endif
 #include "ui/inputbox.h"
 #include "ui/main.h"
 #include "ui/menu.h"
@@ -57,6 +60,10 @@ void (*UI_DisplayFunctions[])(void) = {
 #ifdef ENABLE_AIRCOPY
     [DISPLAY_AIRCOPY] = &UI_DisplayAircopy,
 #endif
+
+#ifdef ENABLE_REGA
+    [DISPLAY_REGA] = &UI_DisplayREGA,
+#endif
 };
 
 static_assert(ARRAY_SIZE(UI_DisplayFunctions) == DISPLAY_N_ELEM);