[ARM] 3063/1: allow slave ixp2000 cpu reset

Patch from Lennert Buytenhek

On the ixdp2x00, the slave CPU is currently not allowed to reset itself
for fear that it will do something 'funky' on the PCI bus.  This fear is
ungrounded -- the slave CPU is wired up such that a CPU reset will not
cause a PCI bus reset to be done.  This patch changes arch_reset() so
that the slave CPU also executes the reset sequence, allowing it to
reboot itself using /sbin/reboot.

Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>