msm: pcie: add SMMU support to calculate SID for PCIe EP

SMMU requires PCIe to provide a SID for each of its endpoint
so that the endpoint can successful transaction on the bus.
This change adds the support for PCIe bus driver to calculate
a SID for its endpoint and give it to the SMMU driver.

Change-Id: I52099bbfed0a38c75b0277b0f58f45f6e6559695
Signed-off-by: Tony Truong <truong@codeaurora.org>