Revert "soong_config: Add flag for msm8974 1440p EGL workaround"

This reverts commit f3f7eb2d.

Support for this in fw/native has been ported in the previous branch
and is very unlikely that will be done or even needed for R.

Change-Id: I9c9709e323d6a27f3c9196887af7ab0ffa1819e9