ixgbe: Restore ESDP settings after MAC reset

ixgbe: Restore ESDP settings after MAC reset

Orabug: 21669416

The I2C mux control relies on the SDP setting in the ESDP register
so it is necessary to restore the value after a MAC reset.  Combine
all this functionality in to a support function.

Signed-off-by: Don Skidmore <donald.c.skidmore@intel.com>
Tested-by: Krishneil Singh <krishneil.k.singh@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
(cherry picked from commit ab5fe0c574edae2831202ce375f8ee2fc6acd002)
Signed-off-by: Brian Maly <brian.maly@oracle.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>