Up to now, HAVE_LCMS would be set only when users would build Weston
with the deprecated cms-static enabled. But we'll start using this in
libweston in the next commits, independently of cms-static being enabled
or not. So always set HAVE_LCMS when the LittleCMS dependency is found.

Signed-off-by: Leandro Ribeiro <leandro.ribeiro@collabora.com>