sfc: Add support for Solarflare 10Xpress SFT9001

Add type codes for the new PHY and rename the SFX7101 type code.

Add definition of clause 22 extension MMD.

Adapt the 10Xpress SFX7101 code to support the SFT9001 as well.
Clean up register definitions.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>