src: use namespace prefix osmo_fd* and osmo_select*

Summary of changes:

s/struct bsc_fd/struct osmo_fd/g
s/bsc_register_fd/osmo_fd_register/g
s/bsc_unregister_fd/osmo_fd_unregister/g
s/bsc_select_main/osmo_select_main/g
diff --git a/openbsc/src/utils/bs11_config.c b/openbsc/src/utils/bs11_config.c
index 8e987de..9cb6897 100644
--- a/openbsc/src/utils/bs11_config.c
+++ b/openbsc/src/utils/bs11_config.c
@@ -903,7 +903,7 @@
 	status_timer.cb = status_timer_cb;
 
 	while (1) {
-		bsc_select_main(0);
+		osmo_select_main(0);
 	}
 
 	abis_nm_bs11_factory_logon(g_bts, 0);
diff --git a/openbsc/src/utils/rs232.c b/openbsc/src/utils/rs232.c
index 43b0dc4..b322e8a 100644
--- a/openbsc/src/utils/rs232.c
+++ b/openbsc/src/utils/rs232.c
@@ -36,7 +36,7 @@
 /* adaption layer from GSM 08.59 + 12.21 to RS232 */
 
 struct serial_handle {
-	struct bsc_fd fd;
+	struct osmo_fd fd;
 	struct llist_head tx_queue;
 
 	struct msgb *rx_msg;
@@ -51,7 +51,7 @@
 
 #define LAPD_HDR_LEN	10
 
-static int handle_ser_write(struct bsc_fd *bfd);
+static int handle_ser_write(struct osmo_fd *bfd);
 
 /* callback from abis_nm */
 int _abis_nm_sendmsg(struct msgb *msg, int to_trx_oml)
@@ -88,7 +88,7 @@
 }
 
 /* select.c callback in case we can write to the RS232 */
-static int handle_ser_write(struct bsc_fd *bfd)
+static int handle_ser_write(struct osmo_fd *bfd)
 {
 	struct serial_handle *sh = bfd->data;
 	struct msgb *msg;
@@ -119,7 +119,7 @@
 #define SERIAL_ALLOC_SIZE	300
 
 /* select.c callback in case we can read from the RS232 */
-static int handle_ser_read(struct bsc_fd *bfd)
+static int handle_ser_read(struct osmo_fd *bfd)
 {
 	struct serial_handle *sh = bfd->data;
 	struct msgb *msg;
@@ -182,7 +182,7 @@
 }
 
 /* select.c callback */
-static int serial_fd_cb(struct bsc_fd *bfd, unsigned int what)
+static int serial_fd_cb(struct osmo_fd *bfd, unsigned int what)
 {
 	int rc = 0;
 
@@ -237,7 +237,7 @@
 	ser_handle->fd.data = ser_handle;
 	ser_handle->delay_ms = delay_ms;
 	ser_handle->bts = bts;
-	rc = bsc_register_fd(&ser_handle->fd);
+	rc = osmo_fd_register(&ser_handle->fd);
 	if (rc < 0) {
 		fprintf(stderr, "could not register FD: %s\n",
 			strerror(rc));