[U-Boot] [PATCH 2/3] 85xx: Fix the wrong CSIZE mask bit

[Liu Dave]

> Ok. I'd prefer we just expand the field to 0x3ff to match the EREF  
> spec since the upper bits are reserved we'll always read them 
> as 0 so no harm.  And we dont have to change the code again in
> the future if we expand into those upper bits.

If match the EREF, it should be 0x7ff.
and it also cause our customers confuse why not use the mask
in e500UM.
Anyway, it is easy to change them to 0x7ff for me.