Some platforms don't want certain devices to be registered, because,
eg, the interface is not wired.  Provide a way for platforms to
prevent various devices from being registered via a devid bitmask in
the platform data.
Acked-by: NNicolas Pitre <nico@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>