cfg80211: allow usermode to query wiphy specific regdom

If a wiphy-idx is specified, the kernel will return the wiphy specific
regdomain, if such exists. Otherwise return the global regdom.

When no wiphy-idx is specified, return the global regdomain as well as
all wiphy-specific regulatory domains in the system, via a new nested
list of attributes.

Add a new attribute for each wiphy-specific regdomain, for usermode to
identify it as such.

Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --cc include/uapi/linux/nl80211.h
Simple merge

diff --cc net/wireless/nl80211.c
Simple merge

diff --cc net/wireless/reg.c
Simple merge

diff --cc net/wireless/reg.h
Simple merge