ARM: 5774/1: Fix Realview ARM1176PB board reboot

This is the fix for proper reboot of Realview ARM1176PB board
when issuing the reboot command. Setting the eighth bit of
control register SYS_RESETCTL to 1 to force a soft reset.
arch_reset() is modified for realview machines to call machine
specific reset function pointers.

Signed-off-by: Philby John <pjohn@in.mvista.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>