OSL: Move external globals from utglobal.c to acpixf.h using ACPI_INIT_GLOBAL/ACPI_GLOBAL.

OSPMs like Linux trend to include all header files but leave empty stub
macros for a feature that is not configured during build.

This patch cleans up global variables that are defined in utglobal.c using
ACPI_INIT_GLOBAL mechanism.
This patch also cleans up global variables that are defined in utglobal.c
using ACPI_GLOBAL mechanism.  Such global variables are not used or should
not be used by Linux.
Such external global variables can be redefined by OSPMs using
ACPI_INIT_GLOBAL/ACPI_GLOBAL macros.  Thus the ACPI_GLOBAL/ACPI_INIT_GLOBAL
mechanisms can be used by OSPM to implement stubs for such external
globals.

No functional changes.  Lv Zheng.

Signed-off-by: Lv Zheng <lv.zheng@intel.com>
OSL: Add configurability for memory allocation macros.

OSPMs like Linux trend to include all header files but leave empty stub
macros for a feature that is not configured during build.

For macros defined to constants or defined to functions without other
functions referencesd (exceptions are ACPI_ALLOCATE_BUFFER and
ACPI_OFFSET-like macros), it is safe to leave them without protections.

By investigation, there are only the following internal/external
functions referenced by the ACPICA macros:
1. C library functions, including string, ctype, stdarg APIs.  Such
   functionalities are always accessbile in the kernel source tree, so
   it is safe to leave them without protected for Linux.
2. ACPICA OSL functions, such functions are designed to be used only by
   ACPICA internal APIs.  But in the Linux kernel, there are references
   in the macros referencing mutex and memory allocation APIs.
   Fortunately, there is no external users directly invoking ACPI_MUTEX
   OSL functions.  But for ACPI_ALLOCATE and ACPI_ALLOCATE_BUFFER, there
   are AcpiOsFree or kfree called as their reversals.  This patch adds
   mechanism to protect ACPICA memory allocation APIs for Linux so that
   Linux can have full control of such macros to configure them into
   no-ops.
3. ACPI_OFFSET and other macros that would access structure members that
   are not accessible under a specific configuration.  Fortunately,
   currently Linux doesn't use such structure members when CONFIG_ACPI
   is disabled.

This patch thus only adds mechanism useful for implementing stubs for
ACPICA provided macros - the configurability of memory allocation APIs.
Lv Zheng.

Signed-off-by: Lv Zheng <lv.zheng@intel.com>
OSL: Add configurability for error message functions.

This patch extends ACPI_HW_DEPENDENT_x mechanism to all error message
related functions so that the OSPMs can have full control to configure
them into stub functions.
This patch also includes code for Linux to use this new mechanism for
the code that is built without CONFIG_ACPI enabled.  Lv Zheng.

Signed-off-by: Lv Zheng <lv.zheng@intel.com>
OSL: Add configurability for debug output functions.

This patch extends ACPI_HW_DEPENDENT_x mechanism to all debugging output
related functions so that the OSPMs can have full control to configure
them into stub functions.
This patch also includes code for Linux to use this new mechanism for
the code that is built without CONFIG_ACPI enabled.  Lv Zheng.

Signed-off-by: Lv Zheng <lv.zheng@intel.com>
OSL: Add configurability for generic external functions.

OSPMs like Linux trend to include all header files but leave empty inline
stub functions for a feature that is not configured during build.
This patch adds wrappers mechanism to be used around ACPICA external
interfaces to facilitate OSPM with such configurability.  Lv Zheng.

Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Merge pull request #24 from zetalog/acpica-stub

ACPICA stub mechanisms