ARM: 8400/1: use virt_to_idmap to get phys_reset address

This patch is to get correct physical address of the reset function for
PAE systems, which use aliased physical memory for booting.

See the "ARM: mm: Introduce virt_to_idmap() with an arch hook" for details.

Signed-off-by: Vitaly Andrianov <vitalya@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>