[ARM] 3300/1: make ixdp2x01 co-exist with other ixp2000 machine types

[ARM] 3300/1: make ixdp2x01 co-exist with other ixp2000 machine types

Patch from Lennert Buytenhek

The ixdp2x01 pci init call doesn't check whether it's really running
on an ixdp2x01, making it impossible to compile one kernel that works
on both the ixdp2x01 and another ixp2000 board.

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>