Massage the way it interfaces a bit to make things more flexible.
The chroma_buf scheme on Sansa Connect and Creative ZVx calling the
lcd_write_yuv420_lines implementation in lcd-as-memframe.S with five params
with a chroma buffer that the function can't use wouldn't work anyway so just
have them use the stock implementation (really, how was that working?).
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@31335 a1c6a512-1295-4272-9138-f99709370657
