Bluetooth: hci_uart: Make struct hci_uart_proto always const

The usage of struct hci_uart_proto should always be const. Change the
function headers and individual protocol drivers.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c
index 50dbaf3..ba3b988 100644
--- a/drivers/bluetooth/hci_ldisc.c
+++ b/drivers/bluetooth/hci_ldisc.c
@@ -48,9 +48,9 @@
 
 #define VERSION "2.2"
 
-static struct hci_uart_proto *hup[HCI_UART_MAX_PROTO];
+static const struct hci_uart_proto *hup[HCI_UART_MAX_PROTO];
 
-int hci_uart_register_proto(struct hci_uart_proto *p)
+int hci_uart_register_proto(const struct hci_uart_proto *p)
 {
 	if (p->id >= HCI_UART_MAX_PROTO)
 		return -EINVAL;
@@ -63,7 +63,7 @@
 	return 0;
 }
 
-int hci_uart_unregister_proto(struct hci_uart_proto *p)
+int hci_uart_unregister_proto(const struct hci_uart_proto *p)
 {
 	if (p->id >= HCI_UART_MAX_PROTO)
 		return -EINVAL;
@@ -76,7 +76,7 @@
 	return 0;
 }
 
-static struct hci_uart_proto *hci_uart_get_proto(unsigned int id)
+static const struct hci_uart_proto *hci_uart_get_proto(unsigned int id)
 {
 	if (id >= HCI_UART_MAX_PROTO)
 		return NULL;
@@ -506,7 +506,7 @@
 
 static int hci_uart_set_proto(struct hci_uart *hu, int id)
 {
-	struct hci_uart_proto *p;
+	const struct hci_uart_proto *p;
 	int err;
 
 	p = hci_uart_get_proto(id);