net/axgbe: alter port speed bit range

net/axgbe: alter port speed bit range

Newer generation Hardware uses the slightly different
port speed bit widths, so alter the existing port speed
bit range to extend support to the newer generation hardware
while maintaining the backward compatibility with older
generation hardware.

The previously reserved bits are now being used which
then requires the adjustment to the BIT values, e.g.:

Before:
   PORT_PROPERTY_0[22:21] - Reserved
   PORT_PROPERTY_0[26:23] - Supported Speeds

After:
   PORT_PROPERTY_0[21] - Reserved
   PORT_PROPERTY_0[26:22] - Supported Speeds

To make this backwards compatible, the existing BIT
definitions for the port speeds are incremented by one
to maintain the original position.

Signed-off-by: Selwin Sebastian <selwin.sebastian@amd.com>
Acked-by: Chandubabu Namburu <chandu@amd.com>