3rd-party/romio cannot be built with RHEL7 GNU compilers from Open MPI v5

[ggouaillardet]

The root cause is romio requires stdatomic.h that is only available from GCC 4.9 (RHEL7 uses GCC 4.8).

`configure --enable-mca-no-build=io-romio314 does not work as expected ...

$ configure --enable-mca-no-build=io-romio341
[...]
checking which components should be disabled... io-romio341
[...]
+++ Configuring MCA framework io
checking for no configure components in framework io...
checking for m4 configure components in framework io... ompio, romio341

--- MCA component io:ompio (m4 configuration macro)
checking for MCA component io:ompio compile mode... static
checking if MCA component io:ompio can compile... yes

--- MCA component io:romio341 (m4 configuration macro)
checking for MCA component io:romio341 compile mode... static
checking if want ROMIO component... yes
checking if MPI profiling is enabled... yes

*** Configuring ROMIO distribution
configure: OPAL configuring in 3rd-party/romio341