Bug#825840: Possible fix for colour invertion on ATY,Rockhopper2

[Mathieu Malaterre <malat@debian.org>]

Hi,

> Well it seems ATY,Rockhopper2 (not Rockhopper) in the Mac Mini is in fact
> a Radeon, and the way the radeonfb driver handles the pallete appears
> to match the cmap_radeon in offb, so perhaps this would work in offb.c

I had time to test this patch yesterday night. It did not work using
`cmap_radeon` codepath. I even tried changing:

out_le32(par->cmap_adr + 0xb4, (red << 16 | green << 8 | blue));

into:

out_le32(par->cmap_adr + 0xb4, (blue << 16 | green << 8 | red));

I am also thinking we are not looking at the right code.

I can see my `printk` messages so I know we are entering the
`cmap_radeon` codepath.

-M