rsl: add new RSL IE to signal temporary overpower

To transfer the temporary overpower value from the BSC to the BTS, a new
RSL IE (RSL_IE_OSMO_TOP_ACCH_CAP) is added.

Change-Id: I31c5be4bceb9140d63ab8e2f197f0acc68699426
Related: SYS#5319
diff --git a/include/osmocom/gsm/protocol/gsm_08_58.h b/include/osmocom/gsm/protocol/gsm_08_58.h
index 9f80816..0182d8d 100644
--- a/include/osmocom/gsm/protocol/gsm_08_58.h
+++ b/include/osmocom/gsm/protocol/gsm_08_58.h
@@ -139,6 +139,11 @@
 #endif
 } __attribute__ ((packed));
 
+/* Osmocom specific IE to negotiate temporary overpower of ACCH channels */
+struct abis_rsl_osmo_temp_ovp_acch_cap {
+	uint8_t overpower_db;
+} __attribute__ ((packed));
+
 /* Chapter 9.1 */
 /* RSL Message Discriminator: RLL */
 #define ABIS_RSL_MDISC_RLL		0x02
@@ -362,6 +367,7 @@
 	/* Osmocom specific */
 	RSL_IE_OSMO_REP_ACCH_CAP= 0x60,
 	RSL_IE_OSMO_TRAINING_SEQUENCE	= 0x61,
+	RSL_IE_OSMO_TEMP_OVP_ACCH_CAP	= 0x62,
 
 	/* ip.access */
 	RSL_IE_IPAC_SRTP_CONFIG	= 0xe0,
diff --git a/src/gsm/rsl.c b/src/gsm/rsl.c
index a7fa81d..e3b21e6 100644
--- a/src/gsm/rsl.c
+++ b/src/gsm/rsl.c
@@ -128,6 +128,7 @@
 		[RSL_IE_SIEMENS_MRPCI]		= { TLV_TYPE_TV },
 		[RSL_IE_OSMO_REP_ACCH_CAP]	= { TLV_TYPE_TLV },
 		[RSL_IE_OSMO_TRAINING_SEQUENCE]	= { TLV_TYPE_TLV },
+		[RSL_IE_OSMO_TEMP_OVP_ACCH_CAP]	= { TLV_TYPE_TLV },
 		[RSL_IE_IPAC_PROXY_UDP]		= { TLV_TYPE_FIXED, 2 },
 		[RSL_IE_IPAC_BSCMPL_TOUT]	= { TLV_TYPE_TV },
 		[RSL_IE_IPAC_REMOTE_IP]		= { TLV_TYPE_FIXED, 4 },