iommu: Allow IOMMU_RESV_DIRECT to work on ARM

For now several ARM drivers do not allow mappings to be created until a
domain is attached. This means they do not technically support
IOMMU_RESV_DIRECT as it requires the 1:1 maps to work continuously.

Currently if the platform requests these maps on ARM systems they are
silently ignored.

Work around this by trying again to establish the direct mappings after
the domain is attached if the pre-attach attempt failed.

In the long run the drivers will be fixed to fully setup domains when they
are created without waiting for attachment.

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/15-v5-1b99ae392328+44574-iommu_err_unwind_jgg@nvidia.com


Signed-off-by: Joerg Roedel <jroedel@suse.de>