[U-Boot] at91: fix a USB problem for AT91SAM9261

[Remy Bohmer]

Hello,

>> Well, the PLLB should be configured correctly by the AT91-bootstrap
>> code (from Atmel).
> no this is the case only if you supposed that you use U-Boot as second
> stage bootloader which is not the case for the PM9263, PM9261 and other
> boards (9263ek too for norflash boot as example)

In that case the description is wrong. It states:
> the USB support for all AT91SAM9261 based boards doesn't work.

Look at the word 'ALL', that mislead me here...

> As already agree with Atmel dev, the bootstrap will have to init only what
> it need to use which is not the case of the USB Host. U-Boot and other binary
> will have to take care of it's own init.

I can agree with that.

Kind regards,

Remy