SF: Don't cache display modes in HWComposer

The display modes should be stored only in DisplayDevice.
Having the state also in HWComposer is unnesesary and hard to
keep in sync with SF, e.g. during hotplug processing of
displays which can change their supported modes.

Any HWC calls which need to validate their parameters need
to go through display device. This additinally makes the
code more undestandable.

Bug: 159590486
Test: presubmit
Change-Id: I40b03c09a5fd6092fca0682d602deb70db022fa5