Staging: VME: Convert TSI148 to use dma_map_single

The DMA functionality fails to work on some Intel based platforms. Some
recent Intel platforms have an IOMMU. Transferring the DMA descriptors,
which were mapped using virt_to_phys(), failed. This patch updates the
driver to use dma_map_single().

Signed-off-by: Martyn Welch <martyn.welch@ge.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>