Introduce a new GUID Hob gEarly16550UartBaseAddressGuid
to cache the base address of the 16550 UART, for when
PCD access is not available.
Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Reviewed-by: Ard Biesheuvel <Ard.Biesheuvel@arm.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>