ACPI 5.1/Disassembler: Add GICC affinity subtable to SRAT table.

Update template for SRAT.
Add ClockDomain to standard CPU affinity subtable.

Mostly by: Hanjun Guo <hanjun.guo@linaro.org>
Headers: Add GTDT flag definitions for the timer subtable.

Mostly by Hanjun Guo <hanjun.guo@linaro.org>