Update FindOpenCL module (support for Mali).
Fixed printT overloads in libclprobe so that...

* Handle cl_ulong
* Use inttypes.h so that we can use appropriate printf formatting.
  I'm assuming that there is a direct correspondance between
  OpenCL C and OpenCL host API types (e.g. cl_ulong and unsigned long
  are of the same size). Reading CL/cl_platform.h this seems to be
  the case.