ynl-gen-c.py: allow directional model for kernel mode

Directional model limitation is only applicable for uapi mode.
For kernel mode, the code is generated correctly using right cmd values
for do/dump requests. Lift the limitation.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20230803111340.1074067-4-jiri@resnulli.us


Signed-off-by: Jakub Kicinski <kuba@kernel.org>