meta-ampere: pldm: remove unnecessary meson option

Any system using PLDM should already `include
conf/distro/include/pldm.inc`, which enables MCTP support as a
side-effect.  By default, the pldm recipe already enables `af-mctp` (the
support for the kernel subsystem):

```
meta-phosphor/recipes-phosphor/pldm/pldm_git.bb
31:PACKAGECONFIG:append:df-mctp = " transport-af-mctp"
```

We shouldn't be setting meson options to begin with, but this one is
already duplicative and ends up being a bad example for others.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I891a4c36eb331f8af6cdef9943e178f3a524d2e7
diff --git a/meta-ampere/meta-common/recipes-phosphor/pldm/pldm_%.bbappend b/meta-ampere/meta-common/recipes-phosphor/pldm/pldm_%.bbappend
index 6381917..4cb41d9 100644
--- a/meta-ampere/meta-common/recipes-phosphor/pldm/pldm_%.bbappend
+++ b/meta-ampere/meta-common/recipes-phosphor/pldm/pldm_%.bbappend
@@ -7,10 +7,6 @@
                                "
 SRC_URI:remove = "file://pldm-softpoweroff"
 
-EXTRA_OEMESON:append = " \
-                        -Dtransport-implementation=af-mctp \
-                       "
-
 do_install:append() {
     install -d ${D}/${datadir}/pldm
     install ${WORKDIR}/host_eid ${D}/${datadir}/pldm/