net: hyperv: dump TX indirection table to ethtool regs

An imbalanced TX indirection table causes netvsc to have low
performance. This table is created and managed during runtime. To help
better diagnose performance issues caused by imbalanced tables, it needs
make TX indirection tables visible.

Because TX indirection table is driver specified information, so
display it via ethtool register dump.

Signed-off-by: Chi Song <chisong@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>