net80211/ifconfig: print hardware device name for wlan interfaces

Add IEEE80211_IOC_IC_NAME to query the ic_name field and in ifconfig
to print the parent interface again. This functionality was lost
around r287197. It helps in case of multiple wlan interfaces and
multiple underlying hardware devices to keep track which wlan
interface belongs to which physical device.

Sponsored by: Rubicon Communications, LLC (d/b/a "Netgate")
Reviewed by: adrian, Idwer Vollering
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D25832