i40e: Extend PHY access with page change flag

Currently FW use MDIO I/F number corresponded with current PF for PHY
access. This code allow to specify used MDIO I/F number.

Add new field - command flags with only one flag for now. Added flag
tells FW that it shouldn't change page while accessing QSFP module, as
it was set manually.

Signed-off-by: Piotr Azarewicz <piotr.azarewicz@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>