Rates reported by HW can be different between chip families. Make the
rate-to-idx translation tables private per family and use them in a
common translation function. Add a global element to help determine
which rates are HW HT-rates.
Signed-off-by: NArik Nemtsov <arik@wizery.com>
Signed-off-by: NLuciano Coelho <coelho@ti.com>