getkey: exclude other keys during a repetition

When a key is being held and repeated, ignore other key presses
until it is released. Without this, new keys would take priority.

This is the desired behavior because pressing other keys by
accident, especially on the directional pad, is common. Besdeis
this is the system's behavior.

src/keysc/getkey.c

@@ -42,6 +42,7 @@ key_event_t getkey_opt(int opt, volatile int *timeout)
 	/* Key press: handle modifiers or return an event */
 	case KEYEV_DOWN:
 		key = ev.key;
+		if(rep_key && key != rep_key) break;
 
 		/* Handle backlight on fx9860g */
 		#ifdef FX9860G