ice: Remove direct write for GLLAN_RCTL_0

Clear PXE mode AQ call (opcode 0x0110) is now supported in FW. So
remove the direct register write to GLLAN_RCTL_0.

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