ARM: 5830/1: ARM: U8500 clock framework

Adds basic clock framework to the U8500 platform.
Currently it just uses the clock lookup table
and add the each entry to the clkdevice. More
complex clock management to follow soon

Signed-off-by: srinidhi kasagar <srinidhi.kasagar@stericsson.com>
Acked-by: Andrea Gallo <andrea.gallo@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>