target-s390x: Fix build for non-linux hosts linux/kvm.h is not always available for compilation. Neither linux/kvm.h nor kvm.h are needed, so remove both which also fixes the build problem for non-linux hosts. Cc: Alexander Graf <agraf@suse.de> Signed-off-by: Stefan Weil <weil@mail.berlios.de> Signed-off-by: Alexander Graf <agraf@suse.de>