[ARM] 3380/1: ixp2000: simplify ixdp2x00_master_npu() check

Patch from Lennert Buytenhek

On the IXDP2x00s, the NPU that is PCI master is always the egress
(i.e. 'master') NPU.  At least on the IXDP2800, both NPUs have flash,
so the ixp2000_has_flash() check in ixdp2x00_master_npu() is useless.

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