edge: Add init functions for gprs_rlc_data_info

Add the functions gprs_rlc_data_info_init_dl/ul which initialise a
gprs_rlc_data_info structure depending on the coding scheme. The
fields num_data_blocks, data_offs_bits, cs, and the data_blocks are
valid after this call. The other fields are set to 0.

The data blocks are initialised to the correct data_len, e == 1
(no extension header field), cv == 15 (not a final block). The other
data block fields are set to 0.

The gprs_rlc_data_block_info can also be initialised separately
by using the gprs_rlc_data_block_info_init function.

Sponsored-by: On-Waves ehf
diff --git a/src/rlc.h b/src/rlc.h
index 0cd7593..5917625 100644
--- a/src/rlc.h
+++ b/src/rlc.h
@@ -99,6 +99,13 @@
 	GprsCodingScheme cs;
 };
 
+void gprs_rlc_data_info_init_dl(struct gprs_rlc_data_info *rlc,
+	GprsCodingScheme cs);
+void gprs_rlc_data_info_init_ul(struct gprs_rlc_data_info *rlc,
+	GprsCodingScheme cs);
+void gprs_rlc_data_block_info_init(struct gprs_rlc_data_block_info *rdbi,
+	GprsCodingScheme cs);
+
 /*
  * I hold the currently transferred blocks and will provide
  * the routines to manipulate these arrays.