hw/i386/intel_iommu: Fix trivial endianness problems

hw/i386/intel_iommu: Fix trivial endianness problems

After reading the guest memory with dma_memory_read(), we have
to make sure that we byteswap the little endian data to the host's
byte order.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20230802135723.178083-2-thuth@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Peter Xu <peterx@redhat.com>
(cherry picked from commit cc2a08480e19007c05be8fe5b6893e20448954dc)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>