MFC: 1.17
MFC: 1.17

- Don't shift the clock frequency in MHz left by 8 before assigning it
  to sbus_mdvec.dv_clock as sbus_mdvec.dv_clock is meant to be specified
  in MHz. While this was a bug it shouldn't have affected FreeBSD/sparc64
  as sbus_mdvec.dv_clock is used to limit the clock rate of chips when
  a machine isn't able to support them at maximum speed which isn't the
  case for sun4u machines.
- Remove the code that checks whether the clock frequency returned by
  sbus_get_clockfreq() is 0 and falls back to 25MHz if it is as that's
  already done in sbus(4).

Approved by:	re (scottl)

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase