OvmfPkg/LsiScsiDxe: Examine the incoming SCSI Request Packet

OvmfPkg/LsiScsiDxe: Examine the incoming SCSI Request Packet

This is the first part of LsiScsiPassThru(). Before processing the SCSI
Request packet, we have to make sure whether the packet is valid or not.

v2: Make LsiScsiPassThru() return EFI_UNSUPPORTED since this function is
    half-implemented

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: <20200717061130.8881-10-glin@suse.com>