arm64: dts: stratix10: Support Ethernet Jumbo frame

Properly specify the RX and TX FIFO size which is important
for Jumbo frames.
Update the max-frame-size to support Jumbo frames.

Signed-off-by: Thor Thayer <thor.thayer@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>