ice: use kernel definitions for IANA protocol ports and ether-types

The well-known IANA protocol port 3260 (iscsi-target 0x0cbc) and the
ether-types 0x8906 (ETH_P_FCOE) and 0x8914 (ETH_P_FIP) are already defined
in kernel header files.  Use those definitions instead of open-coding the
same.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Tony Brelinski <tonyx.brelinski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>