net/mlx5: Relocate function declarations from port.h to mlx5_core.h

net/mlx5: Relocate function declarations from port.h to mlx5_core.h

The port header is a general file under include, yet it
contains declarations for functions that are either not
exported or exported but not used outside the mlx5_core
driver.

To enhance code organization, we move these declarations
to mlx5_core.h, where they are more appropriately scoped.

This refactor removes unnecessary exported symbols and
prevents unexported functions from being inadvertently
referenced outside of the mlx5_core driver.

Signed-off-by: Shahar Shitrit <shshitrit@nvidia.com>
Reviewed-by: Carolina Jubran <cjubran@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20250304160620.417580-2-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>