This patch adds "-x" and "-x -x" options to disable XSDT for acpidump.

The single "-x" can be used to stop using XSDT, RSDT will be forced to find
static tables, note that XSDT will still be dumped. The double "-x" can
stop dumping XSDT, which is useful when the XSDT address reported by RSDP
is pointing to an invalid address.

It is reported there are platforms having broken XSDT shipped, acpidump
will stop working while accessing such XSDT. This patch adds new option so
that users can force acpidump to dump tables listed in the RSDT. Lv Zheng.

Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=73911
Buglink: https://bugs.archlinux.org/task/39811Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Reported-and-tested-by: Bruce Chiarelli <mano155@gmail.com>
Reported-and-tested-by: Spyros Stathopoulos <spystath@gmail.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>