bnxt_en: Add EEE setup code.

1. Add bnxt_hwrm_set_eee() function to setup EEE firmware parameters based
on the bp->eee settings.
2. The new function bnxt_eee_config_ok() will check if EEE parameters need
to be modified due to autoneg changes.
3. bnxt_hwrm_set_link() has added a new parameter to update EEE.  If the
parameter is set, it will call bnxt_hwrm_set_eee().

Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>