net: mscc: ocelot: exclude stats from bulk regions based on reg, not name

net: mscc: ocelot: exclude stats from bulk regions based on reg, not name

We want to introduce elements kept in ocelot->stats that aren't exposed
to the unstructured ethtool -S (so they won't have their name populated),
but are otherwise checked for 32-bit wraparounds by
ocelot_port_update_stats().

This isn't possible today because ocelot_prepare_stats_regions() skips
over ocelot_stat_layout elements with no name. Now that we've changed
struct ocelot_stat_layout to keep the absolute register address rather
than the offset relative to SYS_CNT, we can make use of the unpopulated
"reg" value of 0 to mean that the counter isn't present on the current
switch revision, and skip it from the preparation of bulk regions.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>