devlink: Update TC bandwidth parsing

devlink: Update TC bandwidth parsing

Kernel commit 1bbdb81a9836 ("devlink: Fix excessive stack usage in rate TC bandwidth parsing")
introduced a dedicated attribute set (DEVLINK_RATE_TC_ATTR_*) for entries nested
under DEVLINK_ATTR_RATE_TC_BWS.

Update the parser to reflect this change by validating the nested
attributes and sync the UAPI header to include the changes.

Fixes: c83d1477f8b2 ("Add support for 'tc-bw' attribute in devlink-rate")
Signed-off-by: Carolina Jubran <cjubran@nvidia.com>
Signed-off-by: David Ahern <dsahern@kernel.org>