Supervisor Request Enable (SRE) bit in a PASID entry is for permission
checking on DMA requests. When SRE = 0, DMA with supervisor privilege
will be blocked. However, for in-kernel DMA this is not necessary in that
we are targeting kernel memory anyway. There's no need to differentiate
user and kernel for in-kernel DMA.
Let's use non-privileged (user) permission for all PASIDs used in kernel,
it will be consistent with DMA without PASID (RID_PASID) as well.
Signed-off-by: Jacob Pan<jacob.jun.pan@xxxxxxxxxxxxxxx>