This patch enables the stream ID for the SD/MMC
controllers via dedicated unit register. Thanks to this
change it is possible to configure properly the
IOMMU in OS and use the SD/MMC interface in a guest
Virtual Machine.

Change-Id: I99cbd2c9882eb558ba01405d3d8a3e969f06e082
Signed-off-by: Marcin Wojtas <mw@semihalf.com>
Signed-off-by: Tomasz Nowicki <tn@semihalf.com>