UBIFS: remove xattr Kconnfig option

Remove CONFIG_UBIFS_FS_XATTR configuration option and associated
UBIFS_FS_XATTR ifdefs.

Testing:
       Tested using integck while using nandsim on x86 & MX28 based
       platform with Micron MT29F2G08ABAEAH4 nand.

Signed-off-by: Subodh Nijsure <snijsure@grid-net.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

diff --cc fs/ubifs/Kconfig
Simple merge

diff --cc fs/ubifs/Makefile
Simple merge

diff --cc fs/ubifs/dir.c
Simple merge

diff --cc fs/ubifs/file.c
Simple merge

diff --cc fs/ubifs/journal.c
Simple merge