Allow use of config provided shaders count.

ocl.c

@@ -383,9 +383,15 @@ _clState *initCl(unsigned int gpu, char *name, size_t nameSize)
 		applog(LOG_ERR, "Error %d: Failed to clGetDeviceInfo when trying to get CL_DEVICE_MAX_COMPUTE_UNITS", status);
 		return NULL;
 	}
-	// AMD architechture got 64 compute shaders per compute unit.
-	// Source: http://www.amd.com/us/Documents/GCN_Architecture_whitepaper.pdf
-	clState->compute_shaders = compute_units * 64;
+
+	if (cgpu->shaders) {
+		clState->compute_shaders = cgpu->shaders;
+	}
+	else {
+		// AMD architechture got 64 compute shaders per compute unit.
+		// Source: http://www.amd.com/us/Documents/GCN_Architecture_whitepaper.pdf
+		clState->compute_shaders = compute_units * 64;
+	}
 	applog(LOG_DEBUG, "Max shaders calculated %d", (int)(clState->compute_shaders));
 
 	status = clGetDeviceInfo(devices[gpu], CL_DEVICE_MAX_MEM_ALLOC_SIZE , sizeof(cl_ulong), (void *)&cgpu->max_alloc, NULL);