ANDROID: rtc: class: call hctosys in resource managed registration

A prior commit added a call to hctosys in __rtc_register_device. There
is a duplicated registration path for the resource managed call which
also needs to call hctosys to support modular rtc drivers.

Bug: 156703426
Signed-off-by: Steve Muckle <smuckle@google.com>
Change-Id: Ia454b2315405e3791a922e7191aa10c35800611b