dragon: Add wifi HAL to vintf

Bug: 36886769
Test: compiles (assemble_vintf checks this is formatted correctly and 
works with compatibility matrix)
Change-Id: I1ea547c4394548231f44c146f86e83f4edd411e6
(cherry picked from commit 6fb8e212791e1f1165d286d6f27488ee937cb61b)
1 file changed