net: stmmac: Apply half-duplex-less constraint for DW QoS Eth only

There are three DW MAC IP-cores which can have the multiple Tx/Rx queues
enabled:
DW GMAC v3.7+ with AV feature,
DW QoS Eth v4.x/v5.x,
DW XGMAC/XLGMAC
Based on the respective HW databooks, only the DW QoS Eth IP-core doesn't
support the half-duplex link mode in case if more than one queues enabled:

"In multiple queue/channel configurations, for half-duplex operation,
enable only the Q0/CH0 on Tx and Rx. For single queue/channel in
full-duplex operation, any queue/channel can be enabled."

The rest of the IP-cores don't have such constraint. Thus in order to have
the constraint applied for the DW QoS Eth MACs only, let's move the it'
implementation to the respective MAC-capabilities getter and make sure the
getter is called in the queues re-init procedure.

Fixes: b6cfffa7

 ("stmmac: fix DMA channel hang in half-duplex mode")
Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
Reviewed-by: Romain Gantois <romain.gantois@bootlin.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>