Fix for bug 6691452

Hand merge from ics-aah

> Fix for bug 6691452 : DO NOT MERGE
>
> As it so happens, there seem to be panels out there who disapprove of
> sudden changes in their HDMI clock rate.  In particular, Sony LCD
> panels made from around 2010-2011 (including the Sony GTV panel) seem
> to dislike this behavior.  When exposed to a large jump in the clock
> rate (say from -100pmm to +100ppm in about 30mSec), they seem to
> panic, blank their audio and video, and then resync.  The whole
> panic process takes about 2 seconds.
>
> The HDMI spec says that its clock jitter requirements are defined by
> their differential signalling eye diagram requirements relative to an
> "Ideal Recovery Clock" (see section 4.2.3.1 of the HDMI 1.3a spec).
> Basically, if you pass the eye diagram tests, you pass the clock
> jitter requirements.  We have determined in lab that even being
> extremely aggressive in our VCXO rate changes does not come even close
> to violating the HDMI eye diagrams.  Its just this era of Sony panels
> which seem to be upset by this behavior.
>
> One way or the other, experiments which the GTV devices have seemed to
> indicate that a full range sweep of the VCXO done in 10mSec steps over
> anything faster than 190mSec can cause trouble.  Adding a healthy
> degree of margin to this finding, the fix is to limit the rate of VCXO
> control change such that it never goes at a rate faster than
> FullRange/300mSec.
>
> Change flagged as do not merge due to the code structure changes to master.
> This will need to be merged by hand.
>
> Signed-off-by: John Grossman <johngro@google.com>
> Change-Id: Ibfd361fe1cc2cbd4909489e3317fb12e005c6a75

Change-Id: If62f791c826f1145262a6b546b1dc1f9776c37d8
Signed-off-by: John Grossman <johngro@google.com>