ACPICA: Lint changes

Lint changes
Move RSDT/XSDT pointer extraction to separate function
Warning on 32-bit platforms if XSDT pointers use more than 32 bits.

Signed-off-by: Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>