ARM: 6296/1: clock U300 intcon and timer properly

This removes the quirks to clock the U300 VIC and timer by custom
hooks and moves the control out to the clock framework where it
belongs. This is possible now that clocks are available early.

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