Revert "drm/i915: Don't select BROKEN"

This reverts commit cea35f5.

References: https://lists.freedesktop.org/archives/intel-gfx/2019-November/218878.html
Suggested-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drivers/gpu/drm/i915/Kconfig.debug

@@ -43,6 +43,7 @@ config DRM_I915_DEBUG
 	select DRM_I915_SELFTEST
 	select DRM_I915_DEBUG_RUNTIME_PM
 	select DRM_I915_DEBUG_MMIO
+	select BROKEN # for prototype uAPI
 	default n
 	help
 	  Choose this option to turn on extra driver debugging that may affect