The cmos clock related stuff should really be in MI code.

get_cyclecount() as that results in a saner value and makes schedgraph
much happier on Alpha.  (schedgraph doesn't handle the fact that the
counters are out of sync though)

passing a pointer to an opaque clockframe structure and requiring the
MD code to supply CLKF_FOO() macros to extract needed values out of the
opaque structure, just pass the needed values directly.  In practice this
means passing the pair (usermode, pc) to hardclock() and profclock() and
passing the boolean (usermode) to hardclock_cpu() and hardclock_process().
Other details:
- Axe clockframe and CLKF_FOO() macros on all architectures.  Basically,
  all the archs were taking a trapframe and converting it into a clockframe
  one way or another.  Now they can just extract the PC and usermode values
  directly out of the trapframe and pass it to fooclock().
- Renamed hardclock_process() to hardclock_cpu() as the latter is more
  accurate.
- On Alpha, we now run profclock() at hz (profhz == hz) rather than at
  the slower stathz.
- On Alpha, for the TurboLaser machines that don't have an 8254
  timecounter, call hardclock() directly.  This removes an extra
  conditional check from every clock interrupt on Alpha on the BSP.
  There is probably room for even further pruning here by changing Alpha
  to use the simplified timecounter we use on x86 with the lapic timer
  since we don't get interrupts from the 8254 on Alpha anyway.
- On x86, clkintr() shouldn't ever be called now unless using_lapic_timer
  is false, so add a KASSERT() to that affect and remove a condition
  to slightly optimize the non-lapic case.
- Change prototypeof  arm_handler_execute() so that it's first arg is a
  trapframe pointer rather than a void pointer for clarity.
- Use KCOUNT macro in profclock() to lookup the kernel profiling bucket.

Tested on:	alpha, amd64, arm, i386, ia64, sparc64
Reviewed by:	bde (mostly)

These are referenced in subr_prof.c when building a profiling kernel.

being defined, define and use a new MD macro, cpu_spinwait().  It only
expands to something on i386 and amd64, so the compiled code should be
identical.

Name of the macro found by:	jhb
Reviewed by:	jhb

was just wrong here because the dev_t's are user dev_t's.

Bump __FreeBSD_version accordingly.

Approved by: core