kernel/acpi: Solve ACPI_DEBUG_{CACHE,LOCKS,MEMMAP} building better.

kernel/acpi: Solve ACPI_DEBUG_{CACHE,LOCKS,MEMMAP} building better.

ACPICA 20140627 added a mechanism for having a platform dependent
header that is included _after_ ACPICA headers are included.

So we can now solve compilation with ACPI_DEBUG_{CACHE,LOCKS,MEMMAP}
by adding a new acdragonflyex.h header for the prototypes of the
debug flavors of AcpiOsReleaseObject(), AcpiOsAcquireLock(),
AcpiOsMapMemory() and AcpiOsUnmapMemory() instead of having to put
them into the vendor code (like I did in 3b92a84dc0def, which this
commit reverts).