Revert "libbsc: With the new SAPI states we don't need sacch_deact anymore"

For now we need to keep the sacch_deact in OpenBSC as we couldn't get
the new activation/de-activation code working.

This reverts commit 0c282f5268.

openbsc/include/openbsc/gsm_data_shared.h

@@ -204,6 +204,7 @@ struct gsm_lchan {
 
 	/* Established data link layer services */
 	uint8_t sapis[8];
+	int sacch_deact;
 
 	struct {
 		uint32_t bound_ip;