rdma: Rewrite custom JSON and prints logic to use common API

rdma: Rewrite custom JSON and prints logic to use common API

Instead of doing open-coded solution to generate JSON and prints, let's
reuse existing infrastructure and APIs to do the same as ip/*.

Before this change:
 if (rd->json_output)
     jsonw_uint_field(rd->jw, "sm_lid", sm_lid);
 else
     pr_out("sm_lid %u ", sm_lid);

After this change:
 print_uint(PRINT_ANY, "sm_lid", "sm_lid %u ", sm_lid);

All the print functions are converted to support color but for now the
type of color is COLOR_NONE. This is done as a preparation to addition
of color enable option. Such change will require rewrite of command line
arguments parser which is out-of-scope for this patch.

Signed-off-by: Ido Kalir <idok@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: David Ahern <dsahern@gmail.com>