ACPICA: Cleanup the option of forcing the use of the RSDT.

This change adds a runtime option that will force ACPICA to use the
RSDT instead of the XSDT. Although the ACPI spec requires that an XSDT
be used instead of the RSDT, the XSDT has been found to be corrupt or
ill-formed on some machines.

This option is already in the Linux kernel.  When it is back ported to
ACPICA, code is re-written to follow ACPICA coding style.  This patch
is the generation of the integration.

Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>