MdePkg: Add ACPI 6.3 header file

MdePkg: Add ACPI 6.3 header file

The patch includes the following ACPI 6.3 updates:
 1. Reserve CRAT and CDIT table names in ACPI 6.3 header.
    - ACPI 6.3 January 2019, Table 5-30
    - Mantis ID 1883 (https://mantis.uefi.org/mantis/view.php?id=1883)
 2. Add new processor structure flags in PPTT.
    - ACPI 6.3 January 2019, Section 5.2.29
    - Mantis ID 1870 (https://mantis.uefi.org/mantis/view.php?id=1870)
    - Mantis ID 1934 (https://mantis.uefi.org/mantis/view.php?id=1934)
 3. Add SPE support to MADT.
    - ACPI 6.3 January 2019, Table 5-60
    - Mantis ID 1934 (https://mantis.uefi.org/mantis/view.php?id=1934)
 4. Add 'Hot-plug Capable' flag to APIC.
    - ACPI 6.3 January 2019, Table 5-44, Table 5-47 & Table 5-58
    - Mantis ID 1948 (https://mantis.uefi.org/mantis/view.php?id=1948)
 5. Add CNTHV timer to GTDT.
    - ACPI 6.3 January 2019, Section 5.2.24
    - Mantis ID 1851 (https://mantis.uefi.org/mantis/view.php?id=1851)
 6. Add 'Trigger Order' to Platform Communication Channel Identification
    Structure.
    - ACPI 6.3 January 2019, Section 5.2.28
    - Mantis ID 1867 (https://mantis.uefi.org/mantis/view.php?id=1867)
 7. Add Generic Initiator Affinity Structure to SRAT.
    - ACPI 6.3 January 2019, Section 5.2.16.6
    - Mantis ID 1904 (https://mantis.uefi.org/mantis/view.php?id=1904)
 8. Add 'HMAT Enhancements'.
    - ACPI 6.3 January 2019, Section 5.2.27
    - Mantis ID 1914 (https://mantis.uefi.org/mantis/view.php?id=1914)
    - Mantis ID 1959 (https://mantis.uefi.org/mantis/view.php?id=1959)
 9. Fix generic address structure definition to include all address
    space ID keywords.
   - ACPI 6.3 January 2019, Table 5-25
   - Mantis ID 1965 (https://mantis.uefi.org/mantis/view.php?id=1965)
10. Make Acpi63.h the latest ACPI definition.

Signed-off-by: Krzysztof Koch <krzysztof.koch@arm.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>