pldm: use 'libpldm-only' option
pldm: use 'libpldm-only' option

A compile failure in pldm due to a change in phosphor-dbus-interfaces
broke all of CI.  pldm is imported into our build-unit-test-docker
script because it provides a shared library currently used by
phosphor-debug-collector.  I requested this dependency be removed with
openbmc/openbmc#3749, but in the meantime we should utilize the
`libpldm-only` feature to decrease the surface area of compile fails.

Signed-off-by: Patrick Williams <cbb7353e6d953ef360baf960c122346276c6e320@stwcx.xyz>
Change-Id: I4deaff23327c9e5d32da65a4966c01982c99e909

openbmc/openbmc-build-scripts,openbmc/openbmc-build-scripts