ice: Remove unnecessary checks in add/kill_vid ndo ops

Currently the driver is doing two unnecessary checks. First both ops are
checking if the VLAN ID passed in is less than VLAN_N_VID and second
both ops are checking to see if a port VLAN is configured on the VSI.

The first check is already handled by the 8021q driver so this is an
unnecessary check. The second check is unnecessary because the PF VSI is
never put into a port VLAN.

Remove these checks.

Signed-off-by: Brett Creeley <brett.creeley@intel.com>
Tested-by: Tony Brelinski <tonyx.brelinski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>