uboot-imx

tiny-printf: Tidy up a few nits

- Rename 'w' to 'width' to make it more obvious what it is used for
- Use bool and int types instead of char to avoid register-masking on
32-bit machines

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Stefan Roese <sr@denx.de>