fb: Remove unused FBIOVERTICAL ioctl

Commit 6d1699583d added the FBIOVERTICAL ioctl and said that implementation
in driver will come later.
Since it was in 2001 I think we can remove this.

MFC after:      2 weeks
Sponsored by:   Beckhoff Automation GmbH & Co. KG

sys/dev/fb/fb.c

@@ -738,7 +738,6 @@ fb_commonioctl(video_adapter_t *adp, u_long cmd, caddr_t arg)
 	case FBIO_SETLINEWIDTH:	/* set scan line width in pixel */
 
 	case FBIOGTYPE:
-	case FBIOVERTICAL:
 	case FBIOSCURSOR:
 	case FBIOGCURSOR:
 	case FBIOSCURPOS:

sys/sys/fbio.h

@@ -195,9 +195,6 @@ struct fbcmap {
 #define	FBIOPUTCMAP	_IOW('F', 3, struct fbcmap)
 #define	FBIOGETCMAP	_IOW('F', 4, struct fbcmap)
 
-/* vertical retrace */
-#define	FBIOVERTICAL	_IO('F', 9)
-
 /*
  * Hardware cursor control (for, e.g., CG6).  A rather complex and icky
  * interface that smells like VMS, but there it is....