[ARM] 4881/1: print unrecognised processor ID as part of failure message

If we fail to boot due to an unsupported processor ID, print the
processor ID as part of the failure message.

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Acked-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>