drm/radeon: Fix UBSAN array-index-out-of-bounds for Radeon HD 5430

For pptable structs that use flexible array sizes, use flexible arrays.
Suggested-by: Felix Held <felix.held@amd.com>
Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2894Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/radeon/pptable.h

@@ -74,7 +74,7 @@ typedef struct _ATOM_PPLIB_THERMALCONTROLLER
 typedef struct _ATOM_PPLIB_STATE
 {
     UCHAR ucNonClockStateIndex;
-    UCHAR ucClockStateIndices[1]; // variable-sized
+    UCHAR ucClockStateIndices[]; // variable-sized
 } ATOM_PPLIB_STATE;