ACPI: Get throttling info from BIOS only after evaluating _PDC

Previously _PDC was evaluated later, and thus we'd not get
the chance to tell the BIOS that we can suport FixedHW registers (MSRs)
and the BIOS would always ask us to use System I/O access
for throttling.

Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Li Shaohua <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>