ice(4): Introduce new driver for Intel E800 Ethernet controllers

The ice(4) driver is the driver for the Intel E8xx series Ethernet
controllers; currently with codenames Columbiaville and
Columbia Park.

These new controllers support 100G speeds, as well as introducing
more queues, better virtualization support, and more offload
capabilities. Future work will enable virtual functions (like
in ixl(4)) and the other functionality outlined above.

For full functionality, the kernel should be compiled with
"device ice_ddp" like in the amd64 NOTES file, and/or
ice_ddp_load="YES" should be added to /boot/loader.conf so that
the DDP package file included in this commit can be downloaded
to the adapter. Otherwise, the adapter will fall back to a single
queue mode with limited functionality.

A man page for this driver will be forthcoming.

MFC after: 1 month
Relnotes: yes
Sponsored by: Intel Corporation
Differential Revision: https://reviews.freebsd.org/D21959