net: aquantia: Cleanup hardware access modules

Use direct aq_hw_s *self reference where possible
Eliminate useless abstraction PHAL, duplicated structures definitions,
Simplify nic config structure creation and management.

Signed-off-by: Igor Russkikh <igor.russkikh@aquantia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>