First import (compiles, seems to run correctly)

First import (compiles, seems to run correctly)

Taken from FreeBSD r222544:218590 (patch applied),
not from acpica repository.

One problem shown (no more reproducible, skew build?):
in bootverbose mode 'domain0 misses processors, should be 2, got 1'
sysctl shows hw.acpi.cpu0 only, other cpus are missing;
seems an error in evaluating C009 Method in aml code...

TODO:

* iasl compiler Makefile has to be reworked because of specific
  YASL flags for new files dtparser.[yl]

* 'EVENTHANDLER_INVOKE(power_suspend)' to be integrated in acpi.c

* atomic_load_acq_64 isn't implemented (used in acpi_hpet.c)

* sc->tc.tc_quality isn't available; to be investigated

* acpi_timer_test() improved implementation not integrated

* ACPI_CAP_SMP_C3_NATIVE and CPI_CAP_PX_HW_COORD in acpivar.h
  left out, as FreeBSD don't use it either