[acpica] Export AcpiHwSetFirmwareWakingVector

This is the internal function used to implement AcpiSetFirmwareWakingVector,
the usual API for setting the wake-from-suspend address. That API makes
assumptions about how much of the ACPICA environment is setup that
aren't true for our kernelmode, so we expose the inner mechanism that
bypasses those assumptions.

ZX-1184

Change-Id: I8367fbaf9f51fc93446aa7c8e05b0947073ab887

[powerctl][acpi] Partially implement S-state transition

This implements enough of the S-state transition code to be used for the
shutdown codepath, and for suspending-to-RAM (but not resuming).

ZX-1184

Change-Id: I88aa959db1a77e903e1f98c8d5ea83a825ff24fe

[zx] Magenta -> Zircon

The Great Renaming is here!

Change-Id: I3229bdeb2a3d0e40fb4db6fec8ca7d971fbffb94

[acpica] Check if the DSDT index is valid.

This prevents a crash in the acpisvc if the DSDT table has not been
defined. The hypervisor ulib does not currently define FADT/DSDT.

Change-Id: I1c2af8e806a6f70c5846ddc6d0b910360a9ad6d1

[acpica] Make acpi.h C++ friendly

Change-Id: Ib617260c2bded6c0411c5db87508f352dca44603

[userspace acpi] Add ACPICA service layer implementation

Change-Id: Icfe0c61376f1b76f7444f53b690236f0fb0b4c82

[acpica] Contain ACPICA include path better

Previously acpica was cluttering the global include path. This
diff contains its includes into an acpica directory.

Change-Id: I75bba0ede99259cfb40366ab6170e5281304405f

[magenta] Initial commit