ixl(4)/ixlv(4): Update Intel XL710 PF and VF drivers to ixl-1.11.9 and ixlv-1.5.8

Update the legacy (non-iflib) drivers in stable/11 with recent changes from the
Intel out-of-tree version.

Major changes:

- Support for new BASE-T device with additional link speeds (2.5G and 5G) and EEE
- Additional I2C access methods backported from ixl-iflib
- FW LLDP Agent control with sysctl added for X722 devices (this already
existed for 710 devices)
- MAC/VLAN filters handling has been refactored
- Building and loading if_ixlv as a KLD has been fixed

This is not a MFC since the driver in 12/13 uses iflib, and the decision was
made to not use it in FreeBSD 11 releases.

Submitted by: Krzysztof Galazka <krzysztof.galazka@intel.com>
Sponsored by: Intel Corporation
Differential Revision: https://reviews.freebsd.org/D20290

MFC r333149: ixl(4): Update to 1.9.9-k

Major changes:

- Support for descriptor writeback mode (required by ixlv(4) for AVF support)
- Ability to disable firmware LLDP agent by user
- Fix for TX queue hang when using TSO
- Separate descriptor ring sizes for TX and RX rings

Approved by: re (marius)
Relnotes: yes
Sponsored by: Intel Corporation