mpi/pmix: wakeup eio object only for direct-TCP mode.

Although a degradation observed for some of the message
sizes, overall performance is more stable-growing and
most of the points are improved.

size    UCXv5   UCXv6
1       20.3    19.2
2       18.3    19.2
4       17.7    19.2
8       20.3    19.6
16      20.3    19.9
32      20.3    19.8
64      21.0    20.1
128     21.0    20.5
256     21.7    21.0
512     22.0    21.1
1024    22.0    20.9
2048    23.0    22.1
4096    26.0    25.3
8192    29.0    28.5
16384   31.7    31.2
32768   37.3    37.0
65536   49.0    48.1
131072  74.3    72.6
262144  2227.3  2104.7
524288  2801.0  2722.0
1048576 3795.0  3756.2
2097152 6292.3  6206.3
4194304 10314.3 10281.3

Signed-off-by: Artem Polyakov <artpol84@gmail.com>