gsmtap: Set signal level and SNR fields

lqual (containing C/I value) is passed instead of SNR, but let's have
that better than nothing.

Change-Id: Ibe9502d42c8bd1b984069e7fd805dde87ecbab0c
diff --git a/src/bts.h b/src/bts.h
index 9986bdc..aae8b43 100644
--- a/src/bts.h
+++ b/src/bts.h
@@ -316,6 +316,9 @@
 	void send_gsmtap(enum pcu_gsmtap_category categ, bool uplink, uint8_t trx_no,
 			      uint8_t ts_no, uint8_t channel, uint32_t fn,
 			      const uint8_t *data, unsigned int len);
+	void send_gsmtap_meas(enum pcu_gsmtap_category categ, bool uplink, uint8_t trx_no,
+			      uint8_t ts_no, uint8_t channel, uint32_t fn,
+			      const uint8_t *data, unsigned int len, struct pcu_l1_meas *meas);
 
 	/*
 	 * Below for C interface for the VTY