Extend UNMAP blacklist on all STEC SSD models.

None of existing STEC devices need UNMAP or even support it well, having
many limitations and even hanging sometimes executing those commands.
New devices that may use UNMAP going to be released under HGST name.

MFC after:	3 days
To workaround an errata on certain Pentium Pro CPUs, i386 disables
the local APIC in initializecpu() and re-enables it if the APIC code
decides to use the local APIC after all.  Rework this workaround
slightly so that initializecpu() won't re-disable the local APIC if
it is called after the APIC code re-enables the local APIC.
MFamd64: Use initializecpu() to set various model-specific registers on
AP startup and AP resume (it was already used for BSP startup and BSP
resume).
- Split code to do one-time probing of cache properties out of
  initializecpu() and into initializecpucache().  This is called once on
  the BSP during boot.
- Move enable_sse() into initializecpu().
- Call initializecpu() for AP startup instead of enable_sse() and
  manually frobbing MSR_EFER to enable PG_NX.
- Call initializecpu() when an AP resumes.  In theory this will now
  properly re-enable PG_NX in MSR_EFER when resuming a PAE kernel on
  APs.