Indeed the maximum DMA burst length can be programmed not only for DW
xGMACs, Allwinner EMACs and Spear SoC GMAC, but in accordance with
[1, 2, 3] for Generic DW *MAC IP-cores. Moreover the STMMAC driver parses
the property and then apply the configuration for all supported DW MAC
devices. All of that makes the property being available for all IP-cores
the bindings supports. Let's make sure the PBL-related properties are
validated for all of them by the common DW *MAC DT schema.

[1] DesignWare Cores Ethernet MAC Universal Databook, Revision 3.73a,
    October 2013, p.378.

[2] DesignWare Cores Ethernet Quality-of-Service Databook, Revision 5.10a,
    December 2017, p.1223.

[3] DesignWare Cores XGMAC - 10G Ethernet MAC Databook, Revision 2.11a,
    September 2015, p.469-473.
Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patch.msgid.link/20240628154515.8783-1-fancer.lancer@gmail.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>