Switches the build system to rely on the options and flags generated by
Kconfig to control what gets built and how. Follow on patches will
convert items to be prefixed with CONFIG_. Additionally remove a #define
that resulted in a redefined variable when building for arm.
Signed-off-by: Doug Goldstein <cardoe@cardoe.com> Acked-by: Jan Beulich <jbeulich@suse.com> Acked-by: Ian Campbell <ian.campbell@citrix.com>