MFC r316541, r316544, and r320688 from HEAD to stable/11.

r316541:
Fix a double free in ixgbe_rxeof()

r316544:
Don't overwrite vf->flags variable at the end of ixgbe(4) ixgbe_add_vf()

r320688:
ixgbe(4): Update HEAD (p3) to 3.2.12-k

Includes:

- Support for X550EM devices.
- Support for Bypass adapters.
- Flow Director code moved to separate files
- SR-IOV code moved to separate files
- Netmap code moved to separate files

Sponsored by: Intel Corporation

MFC r314651,r318439,r318440:

r314651:

sys/modules: normalize .CURDIR-relative paths to SRCTOP

This simplifies make output/logic

Tested with: `cd sys/modules; make ALL_MODULES=` on amd64

r318439:

Normalize .PATH on SRCTOP

This will help Jenkins dedupe 9 warnings between the static build and
the module build of ipsec(4).

Missed in SRCTOP conversion in r314651.

MFC with: r314651

r318440:

Normalize SYSDIR on SRCTOP instead of .CURDIR

This is being done to simplify pathing for CFLAGS and source files.

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Add some missing dependencies on pci_iov_if.h.

Sponsored by: EMC / Isilon Storage Division

ixgbe(4): Update to version 3.1.13-k

Add support for two new devices: X552 SFP+ 10 GbE, and the single port
version of X550T.

Submitted by: erj
Reviewed by: gnn
Sponsored by: Intel Corporation
Differential Revision: https://reviews.freebsd.org/D4186

Several build changes for ix and ixv:

- Allow ix and ixv to be built seperately.
- Re-enable building ix for i386 and amd64 archs
- Fix ixv Makefile.

Approved by: jfv (mentor)

Delta D2489 - Add SRIOV support to the Intel 10G driver.

NOTE: This is a technology preview, while it has undergone
development testing, Intel has not yet completed full
validation of the feature. It is being integrated for
early access and customer testing.

Revert last commit, to remove added skeleton tree.

Delta D2489 - Add SRIOV support to the Intel 10G driver.

NOTE: This is a technology preview, while it has undergone development
tests, Intel has not yet completed full validation of the feature.
It is being integrated for early access and customer testing.

Include makefiles necessary to make ixgbe build with the new code.

Originally supposed to be included in r282289.

Differential Revision: D2414

Update to the Intel ixgbe driver:
- Split the driver into independent pf and vf loadables. This is
in preparation for SRIOV support which will be following shortly.
This also allows us to keep a seperate revision control over the
two parts, making for easier sustaining.
- Make the TX/RX code a shared/seperated file, in the old code base
the ixv code would miss fixes that went into ixgbe, this model
will eliminate that problem.
- The driver loadables will now match the device names, something that
has been requested for some time.
- Rather than a modules/ixgbe there is now modules/ix and modules/ixv
- It will also be possible to make your static kernel with only one
or the other for streamlined installs, or both.

Enjoy!

Submitted by: jfv and erj