regulator: core: resolve supply for boot-on/always-on regulators

For the boot-on/always-on regulators the set_machine_constrainst() is
called before resolving rdev->supply. Thus the code would try to enable
rdev before enabling supplying regulator. Enforce resolving supply
regulator before enabling rdev.

Fixes: aea6cb99

 ("regulator: resolve supply after creating regulator")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20210519221224.2868496-1-dmitry.baryshkov@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>