osmo-bsc: Remove hard-coded check for codec preferecne in ASS CMD

When we get an assignment command from the MSC, we no longer have to
check statically for certain codecs, as we have a vty-configured list of
codecs that is checked just below.
diff --git a/openbsc/src/osmo-bsc/osmo_bsc_bssap.c b/openbsc/src/osmo-bsc/osmo_bsc_bssap.c
index 2fbcbe5..a59e2f6 100644
--- a/openbsc/src/osmo-bsc/osmo_bsc_bssap.c
+++ b/openbsc/src/osmo-bsc/osmo_bsc_bssap.c
@@ -349,11 +349,6 @@
 		goto reject;
 	}
 
-	if (data[1] != GSM0808_SPEECH_FULL_PREF && data[1] != GSM0808_SPEECH_HALF_PREF) {
-		LOGP(DMSC, LOGL_ERROR, "ChannelType full not allowed: %d\n", data[1]);
-		goto reject;
-	}
-
 	/*
 	 * go through the list of preferred codecs of our gsm network
 	 * and try to find it among the permitted codecs. If we found