[U-Boot] ARM: omap3: Implement dpll5 (HSUSB clk) workaround for OMAP36xx/AM/DM37xx according to errata sprz318e.

[Andreas Naumann]

Hi Roger,

>
> What are the symptoms you see when this issue triggers?

The symptoms are erroneous USB transaction, seen with a USB port 
analyzer. These only sometimes (not always) stall the USB communication, 
e.g. a USB mass storage device cant be read any longer.

>
> What is the test case to trigger the error? Is it just running any USB I/O for
> long enough time?

Our scenario to reproduce was rebooting a warmed up board (either let it 
run for >5min or heat up in climate chamber).

However, the beagle probably uses a 26 MHz crystal oscillator (our board 
uses 19.2MHz), so the PLL5 dividers may be set in a way that the problem 
never occurs.

> I have a beagle-xm (DM3730 ES1.2) with me and would like to reproduce the error.
>
> cheers,
> -roger
>

regards,
Andreas