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

ixl: remove unnecessary limitations related to netmap

Netmap supports the case where TX rings and RX rings have different size.
Remove unnecessary limitations related to netmap support, making the code
simpler.
Also, check that the value of the hw head index written back from the NIC
is valid.

Reviewed by: erj
Differential Revision: https://reviews.freebsd.org/D18984

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

MFC r320977:

ixl: gcc build errors

MFC r313497: ixl(4): Update to 1.7.12-k.

Refresh upstream driver before impending conversion to iflib.

Major new features:

- Support for Fortville-based 25G adapters
- Support for I2C reads/writes

(To prevent getting or sending corrupt data, you should set
dev.ixl.0.debug.disable_fw_link_management=1 when using I2C
[this will disable link!], then set it to 0 when done. The driver implements
the SIOCGI2C ioctl, so ifconfig -v works for reading I2C data,
but there are read_i2c and write_i2c sysctls under the .debug sysctl tree
[the latter being useful for upper page support in QSFP+]).

- Addition of an iWARP client interface (so the future iWARP driver for
X722 devices can communicate with the base driver).
- Add "options IXL_IW" to kernel config to enable this option.

Sponsored by: Intel Corporation

MFC r303816 r303847
- Update ixl(4) to Intel driver version ixl-1.6.6-k
- Fixup RSS builds of ixl(4) missed during testing.

Approved by: re (gjb)