gsm_trx_burst_if: allow to customize the bind address

Pleviously remote address for DATA interface was also used as the
bind address, what is definitely wrong. Let's change the API a bit
in order to allow one to specify a custom bind address.

Change-Id: I6e5f7b7119ac454217b8dd04f9ee0dd3b23972b6
diff --git a/include/grgsm/misc_utils/udp_socket.h b/include/grgsm/misc_utils/udp_socket.h
index 15b2c66..d1ceb9f 100644
--- a/include/grgsm/misc_utils/udp_socket.h
+++ b/include/grgsm/misc_utils/udp_socket.h
@@ -53,8 +53,9 @@
 
     public:
       udp_socket(
-        const std::string &remote_addr,
+        const std::string &bind_addr,
         const std::string &src_port,
+        const std::string &remote_addr,
         const std::string &dst_port,
         size_t mtu);
       ~udp_socket();