Revert "Merge "Adapt GOP size threshold to the allowed layer depth""

Revert "Merge "Adapt GOP size threshold to the allowed layer depth""

This reverts commit 5efde3914f1a85061e51bc8d96984216e976e90c, reversing
changes made to 3a291593726a3f0eff5e59983e84de20d0bf294c.

This is badly broken and may help somewhat for multi-layer but is hurting
massively in single layer encodes.

I ran this through this morning and while it often helps in SSIM it is badly down
for global PSNR and PSNR-HVS with some clips down by 35-40%. This is in line
with previous experiments where I have found that a bigger boost helps SSIM
but hurts PSNR and PSNR HVS.

I was also working on changes to the I factor that gave some improvements
in single layer though these were based upon the active Q mostly. I also have
looked at a bug for the first group where int_lbq is not properly defined and
will submit an interim patch for this while I look for a better solution.

In the meantime I think we should revert this.

The (Global PSNR, SSIM, PSNR-HVS) for the patch as is in my runs for
single layer vs a couple of days ago seem to be (-ve is better).

Low res 0.346, -1.475, 0.239
mid res  1.581, -1.300, 1.731 (worst result down by 30-40% in psnr)
hdres 0.665, -0.712, 1.043 (worst result down by 17-19% in psnr)
NF2k 0.927, 0.111, 1.3220 (Worst result down by 5-7% in psnr)

Change-Id: I55952b71b8cfc5a84484b3b659c5f8a530f3a755