regulator: onsemi-ncp6335d: Add regulator driver at subsys initcall

Add the onsemi-ncp6335d regulator driver at subsys initcall
as the regulator_get() is used by acpuclock driver at device initcall.
This resolves the dependency chain.

Signed-off-by: Utsab Bose <ubose@codeaurora.org>
Change-Id: Ia7a18218066486c40080b25d57e979372467d8bd