DEVELOPERS: add Nicholas Sielicki as contact for galileo_defconfig

Nicholas was the most recent person to make significant changes to the
galileo_defconfig, so let's add him as a contact for this defconfig,
so that he receives notification of build failures and gets Cc'ed on
patches.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Nicholas Sielicki <sielicki@yandex.com>
Cc: Ray Kinsella <ray.kinsella@intel.com>
Cc: Padraig James Connolly <padraig.connolly@intel.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>