jtag: remove file driver.h

The only purpose of include file driver.h was to expose the API
to register the adapter's commands.

Move the prototype in adapter.h, already used by openocd.c.

Change-Id: Ie1090c60ef9e5bac5ea187c87bed6e7b08d9671c
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/6645
Tested-by: jenkins
Reviewed-by: Tarek BOCHKATI <tarek.bouchkati@gmail.com>

src/jtag/adapter.h

@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0-or-later */
 /*
+ * Copyright (C) 2005 by Dominic Rath <Dominic.Rath@gmx.de>
  * Copyright (c) 2018 Pengutronix, Oleksij Rempel <kernel@pengutronix.de>
  */
 
@@ -12,6 +13,9 @@
 
 struct command_context;
 
+/** Register the adapter's commands */
+int adapter_register_commands(struct command_context *ctx);
+
 /** Initialize debug adapter upon startup.  */
 int adapter_init(struct command_context *cmd_ctx);