drm/radeon: Use correct path to trace include

The header comment in include/trace/define_trace.h specifies that the
TRACE_INCLUDE_PATH needs to be relative to the define_trace.h header
rather than the trace file including it. Most instances get that wrong
and work around it by adding the $(src) directory to the include path.

While this works, it is preferable to refer to the correct path to the
trace file in the first place and avoid any workaround.
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/radeon/Makefile

@@ -109,5 +109,3 @@ radeon-$(CONFIG_VGA_SWITCHEROO) += radeon_atpx_handler.o
 radeon-$(CONFIG_ACPI) += radeon_acpi.o
 
 obj-$(CONFIG_DRM_RADEON)+= radeon.o
-
-CFLAGS_radeon_trace_points.o := -I$(src)

drivers/gpu/drm/radeon/radeon_trace.h

@@ -204,5 +204,5 @@ DEFINE_EVENT(radeon_semaphore_request, radeon_semaphore_wait,
 
 /* This part must be outside protection */
 #undef TRACE_INCLUDE_PATH
-#define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_PATH ../../drivers/gpu/drm/radeon
 #include <trace/define_trace.h>