Straighten ioctl.h

- include all ioctl subheaders, properly listing all letters;
- change FBD's ioctl calls to use 'B' instead of 'F', in
  preparation of the VND driver.

Change-Id: Ia718979568cc057f47cf505a89238d5b3b6695d4

sys/sys/ioctl.h

@@ -20,7 +20,9 @@
 #include <sys/ioc_memory.h>	/* 'm'			*/
 #include <sys/ioc_tape.h>	/* 'M'			*/
 #include <sys/ioc_sound.h>	/* 's'			*/
-#include <sys/ioc_fb.h>		/* 'F'			*/
+#include <sys/ioc_block.h>	/* 'b'			*/
+#include <sys/ioc_fbd.h>	/* 'B'			*/
+#include <sys/ioc_fb.h>		/* 'V'			*/
 
 #if defined(_NETBSD_SOURCE)
 #define		TIOCDRAIN 	TCDRAIN