canonselphyneo: Add placeholder for the new SELPHY CP1300 model.

Just need the PID.  :)

README

@@ -52,6 +52,7 @@
 
   Work-in-progress Printers:
 
+   Canon SELPHY CP1300
    Citizen CW-02, CY-02, and CX2
    DNP DS80DX
    Fujifilm ASK-300
@@ -258,6 +259,10 @@
 
      CP820, CP910
 
+   Unsupported (Unknown USB PIDs):
+
+     CP1300
+
    Valid commands:
    
      -R                 Reset printer to factory defaults

backend_canonselphyneo.c

@@ -45,6 +45,7 @@
 #define USB_PID_CANON_CP910  0x327a
 #define USB_PID_CANON_CP1000 0x32ae
 #define USB_PID_CANON_CP1200 0x32b1
+#define USB_PID_CANON_CP1300 XXXXX
 
 /* Header data structure */
 struct selphyneo_hdr {
@@ -404,6 +405,7 @@ struct dyesub_backend canonselphyneo_backend = {
 	{ USB_VID_CANON, USB_PID_CANON_CP910, P_CP910, ""},
 	{ USB_VID_CANON, USB_PID_CANON_CP1000, P_CP910, ""},
 	{ USB_VID_CANON, USB_PID_CANON_CP1200, P_CP910, ""},
+//	{ USB_VID_CANON, USB_PID_CANON_CP1300, P_CP910, ""},
 	{ 0, 0, 0, ""}
 	}
 };