Both DisplayOzone and DisplayGLX have SwapControlData declared and
defined. In the future, when both of them will be compiled
(DisplayGLX will be required for Ozone/X11), they will result
in a compilation error stating about multiple definitions of the
struct.

Thus, move that rendergl_utils.

Bug: chromium:1084458
Change-Id: Ib174d0e8de1ac4773c841fe286175358acb15d79
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2210702
Commit-Queue: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>