ARM: 6152/1: ux500 make it possible to disable localtimers

Currently compilation of ux500 fails if you deselect the kernel
feature for localtimers.

Acked-by: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>