mlx5dv_devx_alloc_uar(3) on Linux

The text 70b7d28fd771, as Debian 11 (Bullseye) shipped it.

Allocates a DEVX UAR mlx5dv_devx_free_uar - Frees a DEVX UAR

mlx5dv_devx_alloc_uar(3) on Linux now