net/ice/base: consolidate MAC config set

net/ice/base: consolidate MAC config set

Consolidate implementation of ice_aq_set_mac_cfg for switch mode
and NIC mode. As per the specification, the driver needs to call
set_mac_cfg (opcode 0x0603) to be able to exercise jumbo frames.

Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com>
Signed-off-by: Jeb Cramer <jeb.j.cramer@intel.com>
Signed-off-by: Paul M Stillwell Jr <paul.m.stillwell.jr@intel.com>
Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
Acked-by: Qiming Yang <qiming.yang@intel.com>