igc: Change Device Reset to Port Reset

The _reset_hw_base method switched from port reset (CTRL[26]) to device
reset (CTRL[29]) since the FW was receiving an interrupt on CTRL[29].
FW code was later modified to also receive an interrupt on CTRL[26].
Since certain HW values are not reset to default by CTRL[29], we go back
to CTRL[26] for the HW reset, as it meets all current requirements.

This reverts commit bb4265ec ("igc: Update the MAC reset flow").

Signed-off-by: Sasha Neftin <sasha.neftin@intel.com>
Tested-by: Nechama Kraus <nechamax.kraus@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>