xen-evtchn.unix should depend on xen-evtchn

Without this we get intermittent link failures in downstream projects

Signed-off-by: David Scott <dave.scott@citrix.com>
Regenerate OASIS

Signed-off-by: David Scott <dave.scott@citrix.com>
Merge pull request #11 from djs55/fix-depends

Add missing dependency