libhwc2.1: update doze mode when mode group changes

When resolution is changed, the LP mode in driver may change with a
compatible mode such that we can seamlessly transition into Doze.
Update the LP mode when there's a resolution change in order to know
what mode to use to transition into Doze.

Test: switch resolution, enter/exit AOD
Bug: 204995855
Change-Id: Ib40e743438346c54dfe0957119a33a5e2960ed64
5 files changed