Adding mipmap support in sampler

* sampler mipmap lod/filtering programming
* sampler queries
* clCreateSamplerWithProperties
* fixed point numeric type (e.g. U4.8)

Change-Id: I6b496e6f067f6232bab464ab3ee74af8b00904d3

runtime/api/api.cpp

@@ -967,6 +967,9 @@ cl_sampler CL_API_CALL clCreateSampler(cl_context context,
             normalizedCoords,
             addressingMode,
             filterMode,
+            CL_FILTER_NEAREST,
+            0.0f,
+            std::numeric_limits<float>::max(),
             retVal);
     }