board/slider-cmd.h: Add separate Diva LED cmd

The Chunithm slider has sixteen cells and fifteen (I think?)
vertical lines splitting the cells. Diva does not have these lines,
so presumably the LED data format is different. Need to analyze
this further.

board/slider-cmd.h

@@ -4,9 +4,10 @@
 
 enum {
     SLIDER_CMD_AUTO_SCAN = 0x01,
-    SLIDER_CMD_SET_LED = 0x02,
+    SLIDER_CMD_SET_LED_CHUNI = 0x02,
     SLIDER_CMD_AUTO_SCAN_START = 0x03,
     SLIDER_CMD_AUTO_SCAN_STOP = 0x04,
+    SLIDER_CMD_SET_LED_DIVA = 0x9,
     SLIDER_CMD_RESET = 0x10,
     SLIDER_CMD_GET_BOARD_INFO = 0xF0,
 };