net: stmmac: Enable support for > 32 Bits addressing in XGMAC

net: stmmac: Enable support for > 32 Bits addressing in XGMAC

Currently, stmmac only supports 32 bits addressing for SKB. Enable the
support for upto 48 bits addressing in XGMAC core.

This avoids the use of bounce buffers and increases performance.

Changes from v1:
	- Fallback to 32 bits in failure (Andrew)

Signed-off-by: Jose Abreu <[email protected]>
Cc: Joao Pinto <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Giuseppe Cavallaro <[email protected]>
Cc: Alexandre Torgue <[email protected]>
Cc: Andrew Lunn <[email protected]>
Signed-off-by: David S. Miller <[email protected]>