fbdev: stifb: Fall back to cfb_fillrect() on 32-bit HCRX cards

When the text console is scrolling text upwards it calls the fillrect()
function to empty the new line. The current implementation doesn't seem
to work correctly on HCRX cards in 32-bit mode and leave garbage in that
line instead. Fix it by falling back to standard cfb_fillrect() in that
case.

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org>