hwc: Use dirtyRect details in solid fill

No need to clear a non updating region in case of swapRect.
Use dirtyRect value of updating layer to achieve this.
Before using dirtyRect value map it to respective displayFrame,
as dirtyRect is with respect to sourceCrop.

Change-Id: Ie5782a039f7075396e30405070f12ce2443c0a82
3 files changed