edge: Extend gprs_rlcmac_dl_tbf::handle by egprs_ms_class

The multislot (MS) class and the EGPRS MS class can also be passed
via BSSGP in an MS Radio Access Capability element which can
optionally be contained in a DL-UNITDATA PDU. While this case is fully
supported for GPRS, the EGPRS MS class in BSSGP messages is ignored.

This commit extends gprs_rlcmac_dl_tbf::handle to pass the EGPRS MS
class, too.

Note, that the EGPRS class is not yet taken from the CSN.1 RA
capability and is always set to 0. Note also, that append_data
still uses ms_class only.

Sponsored-by: On-Waves ehf
diff --git a/src/gprs_bssgp_pcu.cpp b/src/gprs_bssgp_pcu.cpp
index cce184d..a7391d9 100644
--- a/src/gprs_bssgp_pcu.cpp
+++ b/src/gprs_bssgp_pcu.cpp
@@ -148,6 +148,8 @@
 
 	/* parse ms radio access capability */
 	uint8_t ms_class = parse_ra_cap_ms_class(tp);
+	/* TODO: Get the EGPRS class from the CSN.1 RA capability */
+	uint8_t egprs_ms_class = 0;
 
 	/* get lifetime */
 	uint16_t delay_csec = 0xffff;
@@ -179,7 +181,7 @@
 	LOGP(DBSSGP, LOGL_INFO, "LLC [SGSN -> PCU] = TLLI: 0x%08x IMSI: %s len: %d\n", tlli, imsi, len);
 
 	return gprs_rlcmac_dl_tbf::handle(the_pcu.bts, tlli, tlli_old, imsi,
-			ms_class, delay_csec, data, len);
+			ms_class, egprs_ms_class, delay_csec, data, len);
 }
 
 int gprs_bssgp_pcu_rx_paging_ps(struct msgb *msg, struct tlv_parsed *tp)