OvmfPkg/LsiScsiDxe: Map DMA buffer

OvmfPkg/LsiScsiDxe: Map DMA buffer

Map DMA buffer and perpare for the implementation of LsiScsiPassThru().

v2:
  - Replace 0x10000 with SIZE_64KB macro for the DMA buffer data array
  - Remove DUAL_ADDRESS_CYCLE from PciIo since we don't really need
    64-bit DMA address

Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Signed-off-by: Gary Lin <glin@suse.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20200717061130.8881-9-glin@suse.com>