Add missed option definition - root user mgmt.

Added missed option definition to enable / disable managing
root user under phosphor-user-manager. Default root user is managed
by phosphor-user-manager, but can be disbaled if needed.

Tested:
1. Verified that root user is listed as an object,
in default build
2. Verified that root user is not listed as an object with
EXTRA_OECONF += "--disable-root_user_mgmt"

Change-Id: Iaf677f36b7cc28b67977881235bd72915943b372
Signed-off-by: Richard Marian Thomaiyar <richard.marian.thomaiyar@linux.intel.com>
1 file changed