net/mlx5: Remove broken and unused mlx5_query_mtppse()

net/mlx5: Remove broken and unused mlx5_query_mtppse()

mlx5_query_mtppse() reads the Event Trigger Pin (MTPPSE) register but
reads the returned arm and mode values from the input buffer 'in'
instead of the output buffer 'out', so it always returns the values
that were written rather than the actual hardware state, making the
query useless.

The function has no in-tree callers. Remove it rather than fix it.

Signed-off-by: Li RongQing <lirongqing@baidu.com>
Reviewed-by: Gal Pressman <gal@nvidia.com>
Link: https://patch.msgid.link/20260615140406.1828-1-lirongqing@baidu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>