jtag: move prototype of adapter init/quit and speed to adapter.h

After moved the code, align the include files.

Change-Id: I514a3020648816810d69f76c2ec4f6e52a1c57ab
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/6643
Tested-by: jenkins
Reviewed-by: Tarek BOCHKATI <tarek.bouchkati@gmail.com>

src/jtag/adapter.h

@@ -10,6 +10,14 @@
 #include <stddef.h>
 #include <stdint.h>
 
+struct command_context;
+
+/** Initialize debug adapter upon startup.  */
+int adapter_init(struct command_context *cmd_ctx);
+
+/** Shutdown the debug adapter upon program exit. */
+int adapter_quit(void);
+
 /** @returns true if adapter has been initialized */
 bool is_adapter_initialized(void);
 
@@ -19,4 +27,28 @@ const char *adapter_usb_get_location(void);
 /** @returns true if USB location string is "<dev_bus>-<port_path[0]>[.<port_path[1]>[...]]" */
 bool adapter_usb_location_equal(uint8_t dev_bus, uint8_t *port_path, size_t path_len);
 
+/** @returns The current JTAG speed setting. */
+int jtag_get_speed(int *speed);
+
+/**
+ * Given a @a speed setting, use the interface @c speed_div callback to
+ * adjust the setting.
+ * @param speed The speed setting to convert back to readable KHz.
+ * @returns ERROR_OK if the interface has not been initialized or on success;
+ *  otherwise, the error code produced by the @c speed_div callback.
+ */
+int jtag_get_speed_readable(int *speed);
+
+/** Attempt to configure the interface for the specified KHz. */
+int jtag_config_khz(unsigned khz);
+
+/**
+ * Attempt to enable RTCK/RCLK. If that fails, fallback to the
+ * specified frequency.
+ */
+int jtag_config_rclk(unsigned fallback_speed_khz);
+
+/** Retrieves the clock speed of the JTAG interface in KHz. */
+unsigned jtag_get_speed_khz(void);
+
 #endif /* OPENOCD_JTAG_ADAPTER_H */