ice: Rename enum ice_pkt_flags values

enum ice_pkt_flags contains values such as ICE_PKT_FLAGS_VLAN and
ICE_PKT_FLAGS_TUNNEL, but actually the flags words which they refer to
contain a range of unrelated values - e.g. word 0 (ICE_PKT_FLAGS_VLAN)
contains fields such as from_network and ucast, which have nothing to do
with VLAN. Rename each enum value to ICE_PKT_FLAGS_MDID<number>, so it's
clear in which flags word does some value reside.

Signed-off-by: Marcin Szycik <marcin.szycik@linux.intel.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Tested-by: Sujai Buvaneswaran <sujai.buvaneswaran@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>