Remove $FreeBSD$: one-line sh pattern

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

NVME support is only for x86 and powerpc64.

Implement MK_NVME now that the expression for where NVMe is
complicated. Default it to "yes" for x86 and powerpc64 and
no everywhere else. Use it in camcontrol to define WITH_NVME
for those platforms where we support nvme.

This should fix the newly introduced nvme files to camcontrol
which were building everywhere.

Pointy Hat To: imp
Sponsored by: Netflix

Build nvmecontrol on powerpc64

The nvme driver is compiled for powerpc64 already, and the one fix required
to build nvmecontrol on powerpc64 was fixed in r334754.

Add bsdlabel and fdisk to powerpc64

Submitted by: Wojciech Macek <wma@semihalf.org>
Obtained from: Semihalf
Sponsored by: IBM, QCM Technologies