iommu/arm-smmu: Support for Extended Stream ID (16 bit)

It is the time we have the real 16-bit Stream ID user, which is the
ThunderX. Its IO topology uses 1:1 map for Requester ID to Stream ID
translation for each root complex which allows to get full 16-bit
Stream ID.  Firmware assigns bus IDs that are greater than 128 (0x80)
to some buses under PEM (external PCIe interface).  Eventually SMMU
drops devices on that buses because their Stream ID is out of range:

  pci 0006:90:00.0: stream ID 0x9000 out of range for SMMU (0x7fff)

To fix above issue enable the Extended Stream ID optional feature
when available.

Reviewed-by: Tomasz Nowicki <tomasz.nowicki@caviumnetworks.com>
Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org>
Tested-by: Tomasz Nowicki <tomasz.nowicki@caviumnetworks.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>