cfg80211: add CONFIG_CFG80211_CERTIFICATION_ONUS

cfg80211: add CONFIG_CFG80211_CERTIFICATION_ONUS

This adds CONFIG_CFG80211_CERTIFICATION_ONUS which is to
be used for features / code which require a bit of work on
the system integrator's part to ensure that the system will
still pass 802.11 regulatory certification. This option is
also usable for researchers and experimenters looking to add
code in the kernel without impacting compliant code.

We'd use CONFIG_EXPERT alone but it seems that most standard
Linux distributions are enabling CONFIG_EXPERT already. This
allows us to define 802.11 specific kernel features under a
flag that is intended by design to be disabled by standard
Linux distributions, and only enabled by system integrators
or distributions that have done work to ensure regulatory
certification on the system with the enabled features.

Signed-off-by: Luis R. Rodriguez <mcgrof@qca.qualcomm.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>