[ARM] 4821/1: RealView: Remove the platform dependencies from localtimer.c

This patch removes the TWD_BASE macro used to set up and configure the
local timers on ARM11MPCore. The twd_base_addr and twd_size variables
are defined in localtimer.c and set from the realview_eb_init function.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>