meta-facebook: prep for new override syntax

Ran `scripts/contrib/convert-overrides.py` from upstream Yocto and
fixed up a few by hand that were missed.

Tested: Built bletchley and tiogapass.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I0489ba007132901697e4ef1a29b03a3591b3ee3b
diff --git a/meta-facebook/recipes-phosphor/sel-logger/phosphor-sel-logger_%.bbappend b/meta-facebook/recipes-phosphor/sel-logger/phosphor-sel-logger_%.bbappend
index ac98c7c..ca35bcb 100644
--- a/meta-facebook/recipes-phosphor/sel-logger/phosphor-sel-logger_%.bbappend
+++ b/meta-facebook/recipes-phosphor/sel-logger/phosphor-sel-logger_%.bbappend
@@ -1 +1 @@
-PACKAGECONFIG_append = " log-threshold log-pulse"
+PACKAGECONFIG:append = " log-threshold log-pulse"