libpayload: cbgfx: Replace bilinear resampling with Lanczos

This patch improves the image resampling (scaling) code in CBGFX to use
the Lanczos algorithm that is widely considered the "best" resampling
algorithm (e.g. also the first choice in Python's PIL library). It is of
course much more elaborate and therefore slower than bilinear
resampling, but a lot of the difference can be made up with
optimizations, and the resulting code was found to still produce
acceptable speeds for existing Chrome OS UI use cases. Nevertheless, if
this should be too slow for anyone there's also an option to tune it
down a little (but still much better than bilinear).

Signed-off-by: Julius Werner <jwerner@chromium.org>
Change-Id: Idde6f61865bfac2801ee4fff40ac64e4ebddff1a
---
M payloads/libpayload/Kconfig
M payloads/libpayload/drivers/video/graphics.c
2 files changed, 303 insertions(+), 85 deletions(-)