net/mlx5: Cleanup kTLS function names and their exposure

The _accel_ part of the function is not relevant anymore, so rename kTLS
functions to be without it, together with header cleanup to do not have
declarations that are not used.

Link: https://lore.kernel.org/r/72319e6020fb2553d02b3bbc7476bda363f6d60c.1649073691.git.leonro@nvidia.com


Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>