net: stmmac: Print more information in DebugFS DMA Capabilities file

DMA Capabilites have grown but the DebugFS that shows this info has not
been updated. Lets add the missing information.

Signed-off-by: Jose Abreu <Jose.Abreu@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>