Fix whitespace in binding-parent
Fix whitespace in binding-parent

Whitespace should be four spaces, as it is the norm across project.

Change-Id: Iba62064a397cb8b28713eb45eabdd8d1ad5d928e
Signed-off-by: Robert Varga <b8bd3df785fdc0ff42dd1710c5d91998513c57ef@cisco.com>

NovusTheory/yangtools,opendaylight/yangtools,522986491/yangtools,opendaylight/yangtools