i40e: Remove 100 Mbps SGMII support for X722

This patch fixes the problem where driver shows 100 Mbps as a supported speed,
and allows it to be configured for advertising on X722 devices. This patch
fixes the problem by not setting the 100 Mbps SGMII flag for X722 devices.

Without this patch, the user incorrectly thinks that 100 Mbps is supported
and hence might try to advertise it on X722 devices when it is actually not
a supported speed.

Change-ID: I8c3d7c4251a9402d98994ed29749b7b895a0f205
Signed-off-by: Harshitha Ramamurthy <harshitha.ramamurthy@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>