regulator: core: Fix off-on-delay-us for always-on/boot-on regulators

regulator: core: Fix off-on-delay-us for always-on/boot-on regulators

Regulators marked with "regulator-always-on" or "regulator-boot-on"
as well as an "off-on-delay-us", may run into cycling issues that are
hard to detect.

This is caused by the "last_off" state not being initialized in this
case.

Fix the "last_off" initialization by setting it to the current kernel
time upon initialization, regardless of always_on/boot_on state.

Signed-off-by: Christian Kohlschütter <christian@kohlschutter.com>
Link: https://lore.kernel.org/r/FAFD5B39-E9C4-47C7-ACF1-2A04CD59758D@kohlschutter.com
Signed-off-by: Mark Brown <broonie@kernel.org>