iommu/fsl: Add additional iommu attributes required by the PAMU driver.
Added the following domain attributes for the FSL PAMU driver:
1. Added new iommu stash attribute, which allows setting of the
LIODN specific stash id parameter through IOMMU API.
2. Added an attribute for enabling/disabling DMA to a particular
memory window.
3. Added domain attribute to check for PAMUV1 specific constraints.