The Microsoft Debug Port Table 2 (DBG2) specification revision May 31, 2017 adds support for 16550-compatible Serial Port Subtype with parameters defined in Generic Address Structure (GAS) [1] Reflect that in the EDK2 headers. [1] https://docs.microsoft.com/en-us/windows-hardware/drivers/bringup/acpi-debug-port-table Signed-off-by: Marcin Wojtas <mw@semihalf.com> Reviewed-by: Samer El-Haj-Mahmoud <Samer.El-Haj-Mahmoud@arm.com> Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn> Reviewed-by: Sunny Wang <sunny.wang@arm.com>