UBUNTU: [Config] Enable CONFIG_M686=y

https://blueprints.launchpad.net/ubuntu/+spec/foundations-m-686-compile

The compilers on the i386 architecture are being set to default to i686.
Reflect the same changes in the kernel by enabling CONFIG_M686=y.

This will also resolve the following bug.

BugLink: http://bugs.launchpad.net/bugs/592495

Signed-off-by: Leann Ogasawara <leann.ogasawara@canonical.com>