ensure that the src property is initialized for subkinds

Enyo-DCO-1.1-Signed-Off-By: Cole Davis (cole.davis@lge.com)
Merge pull request #738 from enyojs/BHV-8906-coledavis

Fix for: BHV-8906

Looks good!

Reviewed-by: Aaron Tam (aaron.tam@lge.com)