UCT: Add option to disable gga (#11507)

* UCT/IB/MLX5: Add option to disable GGA transport

Add a --with-gga/--without-gga configure option to control building the GGA (DPU) MLX5 transport, and gate gga/gga_mlx5.c on a new HAVE_TL_GGA conditional instead of HAVE_MLX5_MMO. Also add the author to AUTHORS.

Signed-off-by: Zhenlong Ma <zhenlongm@nvidia.com>

* UCT/IB/MLX5: Address review on GGA configure option

Signed-off-by: Zhenlong Ma <zhenlongm@nvidia.com>

* UCT/IB/MLX5: Change with_gga checking location

Signed-off-by: Zhenlong Ma <zhenlongm@nvidia.com>

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Signed-off-by: Zhenlong Ma <zhenlongm@nvidia.com>