net: stmmac: update MAC capabilities when tx queues are updated

Upon boot up, the driver will configure the MAC capabilities based on
the maximum number of tx and rx queues. When the user changes the
tx queues to single queue, the MAC should be capable of supporting Half
Duplex, but the driver does not update the MAC capabilities when it is
configured so.

Using the stmmac_reinit_queues() to check the number of tx queues
and set the MAC capabilities accordingly.

Fixes: 0366f7e0

 ("net: stmmac: add ethtool support for get/set channels")
Cc: <stable@vger.kernel.org> # 5.17+
Signed-off-by: Michael Sit Wei Hong <michael.wei.hong.sit@intel.com>
Signed-off-by: Gan, Yi Fang <yi.fang.gan@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>