[si] Make it possible to set the NECI value...

Allow to configure the NECI value... and change code
that is relying on the NECI value.
diff --git a/openbsc/src/bsc_init.c b/openbsc/src/bsc_init.c
index bb1e382..d11cde5 100644
--- a/openbsc/src/bsc_init.c
+++ b/openbsc/src/bsc_init.c
@@ -956,6 +956,10 @@
 	type_4->cell_sel_par.ms_txpwr_max_ccch =
 			ms_pwr_ctl_lvl(bts->band, bts->ms_max_power);
 
+	/* Set NECI to influence channel request */
+	type_3->cell_sel_par.neci = bts->network->neci;
+	type_4->cell_sel_par.neci = bts->network->neci;
+
 	if (bts->cell_barred) {
 		type_1->rach_control.cell_bar = 1;
 		type_2->rach_control.cell_bar = 1;