LinuxKPI: 802.11: enhance lkpi_scan_ies_add() for HT and VHT

Add code (currently disabled by #ifdef) for HT and VHT to
lkpi_scan_ies_add(). Switch to a local variable for ic given
the new code also needs the value.

Sponsored by: The FreeBSD Foundation
Approved by: re (cperciva)

(cherry picked from commit 3dd980267f4e53df259eb6d322e7332a8bc5bb0a)
(cherry picked from commit 28fbc0caa49b0fb119cc34a704d5437d63f479a3)