ARM: 7602/1: Pass real "__machine_arch_type" variable to setup_machine_tags() procedure

This modification is needed to proper boot the custom machines with
the IDs that are not described in the mach-types.h table.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>