ixgbe: handle IXGBE_VF_FEATURES_NEGOTIATE mbox cmd

ixgbe: handle IXGBE_VF_FEATURES_NEGOTIATE mbox cmd

Send to VF information about features supported by the PF driver.

Increase API version to 1.7.

Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Signed-off-by: Jedrzej Jagielski <jedrzej.jagielski@intel.com>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://patch.msgid.link/20251009-jk-iwl-net-2025-10-01-v3-5-ef32a425b92a@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>