ice: Call ice_aq_set_mac_cfg

As per the specification, the driver needs to call set_mac_cfg
(opcode 0x0603) to be able to exercise jumbo frames. Call the
function during initialization and the post reset rebuild flow.

Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>