cfg80211: Add backport support for new cfg80211 roam event

This change adds a macro to indicate backport support for the new
cfg80211_roamed API which unifies the old APIs cfg80211_roamed and
cfg80211_roamed_bss and takes a structure to send roam information to
kernel.

Change-Id: Ic6bef5169e606e4fd6a20b24e0dc589cb2b0f964
CRs-Fixed: 2081129
Signed-off-by: Vidyullatha Kanchanapally <vidyullatha@codeaurora.org>