Current ARM SMMU probe functions intermingle HW and DT probing
in the initialization functions to detect and programme the ARM SMMU
driver features. In order to allow probing the ARM SMMU with other
firmwares than DT, this patch splits the ARM SMMU init functions into
DT and HW specific portions so that other FW interfaces (ie ACPI) can
reuse the HW probing functions and skip the DT portion accordingly.

This patch implements no functional change, only code reshuffling.
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: NWill Deacon <will.deacon@arm.com>
Reviewed-by: NRobin Murphy <robin.murphy@arm.com>
Reviewed-by: NTomasz Nowicki <tn@semihalf.com>
Tested-by: NHanjun Guo <hanjun.guo@linaro.org>
Tested-by: NTomasz Nowicki <tn@semihalf.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Hanjun Guo <hanjun.guo@linaro.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>