iavf: remove compatibility code and address some warnings

Code for pre-11 FreeBSD versions is removed.
Also removed are macros that are not used anymore and "i" variable
does not shadow anymore other "i" variable.

Differential Revision: https://reviews.freebsd.org/D41547
Approved by: erj

sys: Remove $FreeBSD$: one-line .c comment pattern

Remove /^/[*/]\s*\$FreeBSD\$.*\n/

iavf: purge EOL release compatibility

Drop code that differentiated between FreeBSD 10 and 11

Reviewed by: imp
Pull Request: https://github.com/freebsd/freebsd-src/pull/603
Differential Revision: https://reviews.freebsd.org/D35560

Mechanically convert iavf(4) to IfAPI

Reviewed by: erj
Sponsored by: Juniper Networks, Inc.
Differential Revision: https://reviews.freebsd.org/D37858

iavf(4): Include RSS header file when RSS is defined

This should unbreak the kernel build when "options RSS" is
defined in the kernel configuration, and make the feature work.

Signed-off-by: Eric Joyner <erj@FreeBSD.org>

Reported by: adrian@
Sponsored by: Intel Corporation

iavf(4): Split source and update to 3.0.26-k

The iavf(4) driver now uses a different source base from ixl(4), since
it will be the standard VF driver for new Intel Ethernet products going
forward, including ice(4). It continues to use the iflib framework
for network drivers.

Since it now uses a different source code base, this commit adds a new
sys/dev/iavf entry, but it re-uses the existing module name so no
configuration changes are necessary.

Signed-off-by: Eric Joyner <erj@FreeBSD.org>

Reviewed by: kbowling@
Tested by: lukasz.szczepaniak@intel.com
Sponsored by: Intel Corporation
Differential Revision: https://reviews.freebsd.org/D28636