regulator: bd718x7: Add enable times

Use the typical startup times from the data sheet so boards get a
reasonable default. Not setting any enable time can lead to board hangs
when e.g. clocks are enabled too soon afterwards.

This fixes gpu power domain resume on the Librem 5.

[Moved #defines into driver, seems to be general agreement and avoids any
cross tree issues -- broonie]

Signed-off-by: Guido Günther <agx@sigxcpu.org>
Reviewed-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Link: https://lore.kernel.org/r/41fb2ed19f584f138336344e2297ae7301f72b75.1608316658.git.agx@sigxcpu.org


Signed-off-by: Mark Brown <broonie@kernel.org>