ARM: OMAP4: Fix the init code to have OMAP4460 errata available in DT build

OMAP4460 ROM code bug needs the GIC distributor and local timer
bases to be available for the bug work around. In current code, dt
case these bases are not initialized leading to failure of the
errata work-around.

Fix it by extracting the bases from dt blob and populating them.

Reported-by: Sourav Poddar <sourav.poddar@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>