iommu/iommu-debug: Rename profiling device functions

The functions for iommu/devices/<device>/profiling don't actually have
the word `profiling' in the name, which will be confusing as we add more
files to that directory.  Rename them for clarity.

Change-Id: Ic57d9400d8784d2cbd667185c5b2b0e1275461dd
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>