package/mdadm: bump version to 4.0

package/mdadm: bump version to 4.0

This version of mdadm can optionally use the corosync and libdlm
packages. However, it checks for their presence by directly probing the
host /usr/include, which fails for cross-compilation:

http://git.neil.brown.name/?p=mdadm.git;a=commitdiff;h=7716570e6d906e7326f83d466f6ba73009649d03#patch2
http://git.neil.brown.name/?p=mdadm.git;a=commitdiff;h=d15a1f72bd92bc4724ee94b2ae8132633ffeb72b#patch1

Since Buildroot doesn't package either corosync nor libdlm, disable
them explicitly with -DNO_COROSYNC -DNO_DLM.

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>