[PATCH] kconfig: PRINTK_TIME depends on PRINTK

Make PRINTK_TIME depend on PRINTK.  Only display/offer it if PRINTK is
enabled.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>