Remove redundant unlock.

This code was removed from the opensolaris and darwin's
netsmb implementations, in DfBSD it also has been disabled.

PR:		36566, 87859, 139407, 161579, 175557, 178412, 186652
MFC after:	2 weeks
Sponsored by:	Yandex LLC
Add the initial version of if_nf10bmac(4), a driver to support an
NetFPGA-10G Embedded CPU Ethernet Core.

The current version operates on a simple PIO based interface connected
to a NetFPGA-10G port.

To avoid confusion: this driver operates on a CPU running on the FPGA,
e.g. BERI/mips, and is not suited for the PCI host interface.

MFC after:	1 week
Relnotes:	yes
Sponsored by:	DARPA/AFRL