DEVELOPERS: remove Morgan Delestre

DEVELOPERS: remove Morgan Delestre

Morgan's e-mail is bouncing:

"""
This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

  m.delestre@sinters.fr
    retry timeout exceeded
"""

And I was confirmed by CORJON Julien <CORJON.J@ecagroup.com> that
Morgan is no longer at ECA/Sinters.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>