hostapd: Extend the configuration of RRM capabilities

hostapd: Extend the configuration of RRM capabilities

Extend the radio_measurements parameter to save all the supported
RRM capabilities as it's used in RM enabled capabilities element.

Make this parameter not directly configurable via config file (though,
keep the radio_measurements parameter for some time for backwards
compatibility). Instead, add a configuration option to enable neighbor
report via radio measurements. Other features can be added later as
well.

Signed-off-by: David Spinadel <david.spinadel@intel.com>