TI: DaVinci: Updating EMAC driver for DM365, DM646x and DA8XX

The EMAC IP on DM365, DM646x and DA830 is slightly different
from that on DM644x. This change updates the DaVinci EMAC driver
so that EMAC becomes operational on SOCs with EMAC v2.

Signed-off-by: Nick Thompson <nick.thompson@ge.com>
Signed-off-by: Ben Warren <biggerbadderben@gmail.com>