ARM: 5644/1: add bcmring core.c, clock.c, clock.h

add core.c, clock.c, and clock.h in mach-bcmring

implement timer init, clocksource init, amba device init
implement clock set/get enable/disable API
add dummy clkdev.h

Signed-off-by: Leo Chen <leochen@broadcom.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>