Hardware doesn't like minimal horizontal gaps. Scale to full width if
the difference is at most three pixels.
Also, don't scale to odd widths. At least Haswell doesn't like it.
Change-Id: Ic1484eda0f6022cd8a37611fdfb9d2c50b390b72
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/26647
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>