enetc: Fix reporting of h/w packet counters

Noticed some inconsistencies in packet statistics reporting.
This patch adds the missing Tx packet counter registers to
ethtool reporting and fixes the information strings for a
few of them.

Fixes: 16eb4c85

 ("enetc: Add ethtool statistics")
Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Link: https://lore.kernel.org/r/20201204171505.21389-1-claudiu.manoil@nxp.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>