drm/msm/a5xx: Separate A5XX_PC_DBG_ECO_CNTL write from main branch

The "main" if branch where we program the other registers for the
Adreno 5xx family of GPUs should not contain the PC_DBG_ECO_CNTL
register programming because this has logical similarity
differences from all the others.

A later commit will show the entire sense of this.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
Reviewed-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>