msm: pil: Calculate image region and inform drivers

Some processors need to know where in memory their image resides.
Add a new hook for this

 int (*mem_setup)(struct pil_desc *pil, phys_addr_t addr, size_t size)

that pil drivers can implement so they can be informed of where
their image lies in memory. It's expected that drivers will
program an IOMMU or notify the authentication agent with the
information from this callback.

Change-Id: I6169e4376f8c9c155bab149ce14fde3b2548d5cc
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>