ice: Implement devlink port split operations

Allow to configure port split options using the devlink port split
interface. Support port splitting only for port 0, as the FW has
a predefined set of available port split options for the whole device.

Add ice_devlink_port_options_print() function to print the table with
all available FW port split options. It will be printed after each port
split and unsplit command.

Add documentation for devlink port split interface usage for the ice
driver.

Co-developed-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Anatolii Gerasymenko <anatolii.gerasymenko@intel.com>
Tested-by: Gurucharan <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>