iommu : arm-smmu : update MID info in ECATS register

update MID information in ECATS register to help identify ECATS
transactions from regular master traffic.

Change-Id: I9e3bc301d4b37c86eef3cc436dafb5fecf3fe12c
Signed-off-by: Prakash Gupta <guptap@codeaurora.org>