service: use id in probe and get name

service: use id in probe and get name

This commit adds a macro to easily validate a service ID, and then
lookup the service pointer, or return a user-specified error code.
This macro will be heavily used in the following patches as it will
be ID based instead of pointer-based.

The probe_capability function is reworked to use an integer ID instead
of a pointer. Rework the service_get_name() function is updated to use
IDs. Unit tests are updated to keep things compiling after each commit.

Signed-off-by: Harry van Haaren <harry.van.haaren@intel.com>
Acked-by: Pavan Nikhilesh <pbhagavatula@caviumnetworks.com>