Queue profiling and Device timebase equality test (#1150)

Adds test to confirm that the timestamp returned from
clGetEventProfilingInfo for an event on a device and a device
timestamp queried from the same device are in the same timebase.

Fixes #753

Signed-off-by: Ellen Norris-Thompson <ellen.norris-thompson@arm.com>

---------

Signed-off-by: Ellen Norris-Thompson <ellen.norris-thompson@arm.com>

test_conformance/profiling/CMakeLists.txt

@@ -9,6 +9,7 @@ set(${MODULE_NAME}_SOURCES
     copy.cpp
     execute.cpp
     execute_multipass.cpp
+    profiling_timebase.cpp
 )
 
 include(../CMakeCommon.txt)