This reverts commit ba168fc3.

It changes user-visible sysfs interfaces, and breaks some existing user
space applications which apparently rely on the fact that the output
does not contain the "0x" prefix.
Requested-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: NWu Fengguang <fengguang.wu@intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>