Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with:		pfg
MFC After:		3 days
Sponsored by:		Netflix

BIO_READ and BIO_WRITE, we've handled this expanded syntax poorly in
drivers when the driver doesn't support a particular command.  Do a
sweep and fix that.

Reported by:	imp

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Most affect comments, very few have user-visible effects.

- Use callout(9) rather than timeout(9).
- Add a mutex as an I/O lock that protects the adapter and is used
  for the I/O path.
- Add an sx lock as a configuration lock that protects the relationship
  of configured volumes.
- Freeze the request queue when a DMA load is deferred with EINPROGRESS
  and unfreeze the queue when the DMA callback is invoked.
- Explicitly poll the hardware while waiting to submit a command to
  allow completed commands to free up slots in the command ring.
- Remove driver-wide 'initted' variable from mlx_*_fw_handshake() routines.
  That state should be per-controller instead.  Add it as an argument
  since the first caller knows when it is the first caller.
- Remove explicit bus_space tag/handle and use bus_*() rather than
  bus_space_*().
- Move duplicated PCI device ID probing into a  mlx_pci_match() routine.
- Don't check for PCIM_CMD_MEMEN (the PCI bus will enable that when
  allocating the resource) and use pci_enable_busmaster() rather than
  manipulating the register directly.

Tested by:	no one despite multiple requests (hope it works)

PR: kern/21220
Submitted by: Dennis Lindroos
MFC After: 1 week