rainier: Enable the OpenPower PEL logging plugin

This enables Platform Event Log handling in phosphor-log-manager.

Signed-off-by: Matt Spinler <spinler@us.ibm.com>
Change-Id: I0e9394f54156a856c9e11adedc55f43696dba7c8
diff --git a/meta-witherspoon/recipes-phosphor/logging/phosphor-logging_%.bbappend b/meta-witherspoon/recipes-phosphor/logging/phosphor-logging_%.bbappend
index 5e2dc6c..9dff37d 100644
--- a/meta-witherspoon/recipes-phosphor/logging/phosphor-logging_%.bbappend
+++ b/meta-witherspoon/recipes-phosphor/logging/phosphor-logging_%.bbappend
@@ -1 +1,2 @@
 PACKAGECONFIG_append_witherspoon-128 = " openpower-pels"
+PACKAGECONFIG_append_rainier = " openpower-pels"