Add the ability to pass flags into the iommu_domain_alloc function to specify domain attributes. Change-Id: Ia33aa8d887a57f76d97ab8921385dcc551716846 Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org> [sboyd: Only iommu_domains.c part] Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>