Revert "msm: msm_fb: Fix Regressions because of overmap changes."

This reverts commit 40d83c037cbe0263ebfa20332aa55b8eeb7e1f53.
Revert "Revert "Revert "msm: msm_fb: Map RGB layers to the max possible size."""

This reverts commit 72d52ee75ab867d113315be0bd48e2ceb963de1b.