OMAPDSS: set suppress_bind_attrs

omapdss drivers cannot handle devices being unbound while the devices
are part of a connected display pipeline. Module refcounts are used to
prevent unloading the modules, but one can still manually unbind the
devices via sysfs, causing crash.

Set suppress_bind_attrs to disable the bind/unbind support via sysfs.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>