meta-ibm: use ibm-ac-server MACHINEOVERRIDE

Use an override in bbappends in meta-witherspoon as described and
recommended in the "following best practices when creating layers"
section of the the Yocto development tasks manual.

ibm-ac-server represents common machine configuration shared by all of
IBMs "Accelerated Compute" class of servers.  Apply it wherever any
variables are un-bounded by any override.

This enables more flexible use of meta-witherspoon in build
configurations, and easy addition of machines to the layer.

(From meta-ibm rev: bb0e1d0699a4b9905c053c94af7d882cd71779fc)

Change-Id: I82f7338b0d7a64b5e7a67e19bcdff07f48a332d4
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/meta-ibm/meta-witherspoon/recipes-phosphor/packagegroups/packagegroup-obmc-apps.bbappend b/meta-ibm/meta-witherspoon/recipes-phosphor/packagegroups/packagegroup-obmc-apps.bbappend
index 92b48f9..386c1e6 100644
--- a/meta-ibm/meta-witherspoon/recipes-phosphor/packagegroups/packagegroup-obmc-apps.bbappend
+++ b/meta-ibm/meta-witherspoon/recipes-phosphor/packagegroups/packagegroup-obmc-apps.bbappend
@@ -1,6 +1,5 @@
-RDEPENDS_${PN}-inventory += "openpower-fru-vpd openpower-occ-control phosphor-cooling-type virtual/obmc-gpio-presence"
-RDEPENDS_${PN}-fan-control += "witherspoon-fan-watchdog"
-RDEPENDS_${PN}-extras += "witherspoon-pfault-analysis witherspoon-power-supply-sync phosphor-webui"
+RDEPENDS_${PN}-inventory_append_ibm-ac-server = " openpower-fru-vpd openpower-occ-control phosphor-cooling-type virtual/obmc-gpio-presence"
+RDEPENDS_${PN}-fan-control_append_ibm-ac-server = " witherspoon-fan-watchdog"
+RDEPENDS_${PN}-extras_append_ibm-ac-server = " witherspoon-pfault-analysis witherspoon-power-supply-sync phosphor-webui"
 
-${PN}-software-extras_append_witherspoon = " phosphor-software-manager-sync"
-${PN}-software-extras_append_swift = " phosphor-software-manager-sync"
+${PN}-software-extras_append_ibm-ac-server = " phosphor-software-manager-sync"