Replace ns16550.txt with binding files from Linux kernel. As suggested
by Stephen Warren, we should keep the directory structure, filenames,
and file content identical to the bindings in the Linux kernel.
Signed-off-by: Thomas Chou <thomas@wytron.com.tw>
Acked-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
