drm: unbreak the DRM menu, broken by DRM_EXPORT_FOR_TESTS

Unbreak the DRM menu. This Kconfig symbol does not depend on DRM,
so the menu is broken at that point.

Move the symbol to a location in the Kconfig file so that it does
not break the dependency continuity.

Fixes: 6349120d ("drm: Move EXPORT_SYMBOL_FOR_TESTS_ONLY under a separate Kconfig")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/04221997-79ba-f8a2-4f2d-3c3d9f5219bc@infradead.org

drivers/gpu/drm/Kconfig

@@ -54,9 +54,6 @@ config DRM_DEBUG_MM
 
 	  If in doubt, say "N".
 
-config DRM_EXPORT_FOR_TESTS
-	bool
-
 config DRM_DEBUG_SELFTEST
 	tristate "kselftests for DRM"
 	depends on DRM
@@ -470,6 +467,9 @@ config DRM_SAVAGE
 
 endif # DRM_LEGACY
 
+config DRM_EXPORT_FOR_TESTS
+	bool
+
 # Separate option because drm_panel_orientation_quirks.c is shared with fbdev
 config DRM_PANEL_ORIENTATION_QUIRKS
 	tristate