core/logging.h: Add logging category for jitter buffer

Forthcoming jitter buffer code in libosmo-netif will make use of it.

Change-Id: I2434f9dfa401f736bc62a2ddce920e587cd8c517
diff --git a/src/logging.c b/src/logging.c
index 66074ea..147b1fb 100644
--- a/src/logging.c
+++ b/src/logging.c
@@ -168,6 +168,11 @@
 		.description = "libosmo-mgcp Media Gateway Control Protocol",
 		.enabled = 1, .loglevel = LOGL_NOTICE,
 	},
+	[INT2IDX(DLJIBUF)] = {
+		.name = "DLJIBUF",
+		.description = "libosmo-netif Jitter Buffer",
+		.enabled = 1, .loglevel = LOGL_NOTICE,
+	},
 };
 
 /*! descriptive string for each log level */