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,