Add keyboards for extra media & system keys

keywords.txt

 KEY_MEDIA_PREV_TRACK	LITERAL1
 KEY_MEDIA_STOP	LITERAL1
 KEY_MEDIA_EJECT	LITERAL1
+KEY_MEDIA_PLAY	LITERAL1
+KEY_MEDIA_PAUSE	LITERAL1
+KEY_MEDIA_RECORD	LITERAL1
+KEY_MEDIA_REWIND	LITERAL1
+KEY_MEDIA_FAST_FORWARD	LITERAL1
+KEY_MEDIA_PLAY_SKIP	LITERAL1
+KEY_SYSTEM_POWER_DOWN	LITERAL1
+KEY_SYSTEM_SLEEP	LITERAL1
+KEY_SYSTEM_WAKE_UP	LITERAL1
 KEY_A	LITERAL1
 KEY_B	LITERAL1
 KEY_C	LITERAL1