lima: implement EGL_KHR_partial_update
Tested work with latest weston which will use this extension.
On Amlogic S905X, weston has no problem. But on Allwinner H3, I see cursor disappear occasionally when moving while no problem without this extension. So need more test to see why. I guess it's due to this extension need to create pp stream on the fly, so when the damage region is large (1920x1080 need to build 8100 pp stream entry) and CPU is slow, the build takes too much time.
If this is the reason, we need to set some threshold for building the pp stream on the fly or just full damage.