iwlwifi: Update man pages with card list

Add list of supported names to iwlwifi.4 and an extended list with
PCI IDs and firmware prefix to iwlwififw.4.

Sponsored by: The FreeBSD Foundation
Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D35227

(cherry picked from commit f5539996511eeca7dcf3c9849edda26d85306290)