Moved the MIN() macro to the helper include.

Removed multiple definitions of the MIN() macro from existing
locations and unified with a single definition. Updated sources
to use the shared version.

Signed-off-by: Jon A. Cruz <jonc@osg.samsung.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Bryce Harrington <bryce@osg.samsung.com>