nyx: wait for the first frame to render

Needed for lcd oem clones on oled sku because of no fade in support.

nyx/nyx_gui/frontend/gui.c

@@ -106,6 +106,7 @@ static void _nyx_disp_init()
 
 	// Rotate and copy the first frame.
 	vic_compose();
+	vic_wait_idle();
 
 	// Switch to new window configuration.
 	display_init_window_a_pitch_vic();