phosphor-logging: Fix missing python dependency

The PEL feature depends on python3 at build time to link against the
library, not runtime.

Change-Id: Iaaf4d39828205d8750c2669e2798bff9ea16f009
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/meta-phosphor/recipes-phosphor/logging/phosphor-logging_git.bb b/meta-phosphor/recipes-phosphor/logging/phosphor-logging_git.bb
index 9911eb0..9707559 100644
--- a/meta-phosphor/recipes-phosphor/logging/phosphor-logging_git.bb
+++ b/meta-phosphor/recipes-phosphor/logging/phosphor-logging_git.bb
@@ -63,7 +63,7 @@
 PACKAGECONFIG[openpower-pels] = " \
         -Dopenpower-pel-extension=enabled, \
         -Dopenpower-pel-extension=disabled, \
-        nlohmann-json cli11 pldm, \
+        nlohmann-json cli11 pldm python3, \
         python3, \
         "