Patch from Lennert Buytenhek

The ixp2000 defconfigs are among the few that do not enable module
support by default.  I keep enabling module support by hand for every
new kernel version, so let's just make this change upstream.

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