ehea: Remove num_tx_qps module option

The num_tx_qps module option allows a user to configure a different
number of tx and rx queues. Now the networking stack is multiqueue
aware it makes little sense just to enable the tx queues and not the
rx queues so remove the option.

v3:
[cascardo] fixed conflict with get_stats change

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>