drm: Add standardized boolean props

Not a new type exposed to userspace, just a standard way to create
them since between range, bitmask and enum there's 3 different ways to
pull out a boolean prop.

Also add the kerneldoc for the recently added new prop types, which
Rob forgot all about.

v2: Fixup kerneldoc, spotted by Rob.

Cc: Rob Clark <robdclark@gmail.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 0ecfb7c..c4e36f6 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -1345,6 +1345,8 @@
 					 int64_t min, int64_t max);
 struct drm_property *drm_property_create_object(struct drm_device *dev,
 					 int flags, const char *name, uint32_t type);
+struct drm_property *drm_property_create_bool(struct drm_device *dev, int flags,
+					 const char *name);
 extern void drm_property_destroy(struct drm_device *dev, struct drm_property *property);
 extern int drm_property_add_enum(struct drm_property *property, int index,
 				 uint64_t value, const char *name);