dm: core: allow drivers to refuse to bind

dm: core: allow drivers to refuse to bind

In some cases, drivers may not want to bind to a device. Allow bind() to
return -ENODEV in this case, and don't treat this as an error. This can
be useful in situations where some information source other than the DT
node's main status property indicates whether the device should be
enabled, for example other DT properties might indicate this, or the
driver might query non-DT sources such as system fuses or a version number
register.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Simon Glass <sjg@chromium.org>