Change in coreboot[master]: sb/intel/common: Add common reset handler

[Nico Huber (Code Review)]

Nico Huber has posted comments on this change. ( https://review.coreboot.org/28862 )

Change subject: sb/intel/common: Add common reset handler
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Patch Set 2:

Ok, to clear this up a little. In the current definition by reset.h:

* cpu_reset() was a cpu reset (for Intel) but dropped
  * soft_reset() is a system reset (for Intel)
  * hard_reset() is a full reset (for Intel)
  * global_reset() is not well specified but I bet always the same for Intel (either let the ME do it or do a ME+system reset)

Deviating from this was ok as long as only platform code called the
reset functions (it knew what was implemented as what). But if you
call them from common code (e.g. vboot) they have to match.