tbf: Move TFI selection into alloc_algorithm

Currently the TFI and the TRX have to be determined before the actual TBF
allocation function is called, passing TFI and TRX number as
parameters. This does fit to TFI reuse for different slots, since
this were tightly coupled with the slot selection.

This commit just moves the TFI selection into the alloc_algorithm
functions. The tfi parameter is removed from the the TFI alloc
functions. The trx parameter is changed into use_trx to optionally
limit the trx selection (same semantics like in tfi_find_free).

Sponsored-by: On-Waves ehf
diff --git a/src/gprs_rlcmac.h b/src/gprs_rlcmac.h
index dab3338..3fc95e6 100644
--- a/src/gprs_rlcmac.h
+++ b/src/gprs_rlcmac.h
@@ -97,11 +97,13 @@
 #endif
 int alloc_algorithm_a(struct gprs_rlcmac_bts *bts,
 	struct GprsMs *ms,
-	struct gprs_rlcmac_tbf *tbf, uint32_t cust, uint8_t single);
+	struct gprs_rlcmac_tbf *tbf, uint32_t cust, uint8_t single,
+	int use_trx);
 
 int alloc_algorithm_b(struct gprs_rlcmac_bts *bts,
 	struct GprsMs *ms,
-	struct gprs_rlcmac_tbf *tbf, uint32_t cust, uint8_t single);
+	struct gprs_rlcmac_tbf *tbf, uint32_t cust, uint8_t single,
+	int use_trx);
 #ifdef __cplusplus
 }
 #endif