ide: Fix SC1200 dependencies

The SC1200 is a SoC based on the Geode GX1 32-bit x86 processor, so
its drivers are only needed on this architecture, except for build
testing purpose.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>