UBI: document UBI ioctls

Update the ioctl-numbers.txt file, add UBI and DVB there
(because they use the same ioctl numbers).
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

Documentation/ioctl/ioctl-number.txt

@@ -97,6 +97,7 @@ Code	Seq#	Include File		Comments
 					<http://linux01.gwdg.de/~alatham/ppdd.html>
 'M'	all	linux/soundcard.h
 'N'	00-1F	drivers/usb/scanner.h
+'O'     00-02   include/mtd/ubi-user.h UBI
 'P'	all	linux/soundcard.h
 'Q'	all	linux/soundcard.h
 'R'	00-1F	linux/random.h
@@ -142,6 +143,9 @@ Code	Seq#	Include File		Comments
 'n'	00-7F	linux/ncp_fs.h
 'n'	E0-FF	video/matrox.h          matroxfb
 'o'	00-1F	fs/ocfs2/ocfs2_fs.h	OCFS2
+'o'     00-03   include/mtd/ubi-user.h  conflict! (OCFS2 and UBI overlaps)
+'o'     40-41   include/mtd/ubi-user.h  UBI
+'o'     01-A1   include/linux/dvb/*.h DVB
 'p'	00-0F	linux/phantom.h		conflict! (OpenHaptics needs this)
 'p'	00-3F	linux/mc146818rtc.h	conflict!
 'p'	40-7F	linux/nvram.h