salt: Use NILRT_GIT in SRC_URI
salt: Use NILRT_GIT in SRC_URI

Reference source by NILRT_GIT URI instead git.amer.corp.natinst.com
to facilitate site mirroring of the NILRT source repo.

Signed-off-by: Haris Okanovic <4f2c24956fa4a8756878315db434b9fed29fa615@ni.com>
Natinst-ReviewBoard-ID: 131341

ni/meta-nilrt,ni/meta-nilrt,ni/meta-nilrt,ni/meta-nilrt,ni/meta-nilrt