Add regulator_has_full_constraints() call to poodle board file to let
regulator core know that we do not have any additional regulators left.
This lets it substitute unprovided regulators with dummy ones.

This fixes the following warnings that can be seen on poodle if
regulators are enabled:

ads7846 spi1.0: unable to get regulator: -517
spi spi1.0: Driver ads7846 requests probe deferral
wm8731 0-001b: Failed to get supply 'AVDD': -517
wm8731 0-001b: Failed to request supplies: -517
wm8731 0-001b: ASoC: failed to probe component -517

Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>