bareudp: Handle stats using NETDEV_PCPU_STAT_DSTATS.

Bareudp uses the TSTATS infrastructure (dev_sw_netstats_*()) for RX
packet counters. It was also recently converted to use the device core
stats (dev_core_stats_*()) for RX and TX drops (see commit 788d5d65
("bareudp: Use pcpu stats to update rx_dropped counter.")).

Since core stats are to be avoided in drivers, and for consistency with
VXLAN and Geneve, let's convert packet stats handling to DSTATS, which
can handle RX/TX stats and packet drops. Statistics that don't fit
DSTATS are still updated atomically with DEV_STATS_INC().

Signed-off-by: Guillaume Nault <gnault@redhat.com>
Link: https://patch.msgid.link/0f4f8448db3ff449ac6e939872b28cf3f8982da7.1733313925.git.gnault@redhat.com


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