Bluetooth: hci: added HCI vendor-specific Setup function feature

- Added config BT_HCI_SETUP to enable HCI vendor-specific Setup feature,
- Added pointer to 'setup' function in bt_hci_driver structure.

BT_HCI_SETUP feature is useful when the BT Controller requires execution
of the vendor-specific commands sequence to initialize the BT Controller
before the BT Host executes a Reset sequence. To enable this feature the
CONFIG_BT_HCI_SETUP should be enable.

Fixes #41140

Signed-off-by: Nazar Palamar <nazar.palamar@infineon.com>

drivers/bluetooth/hci/Kconfig

@@ -131,3 +131,16 @@ config BT_DRIVER_QUIRK_NO_AUTO_DLE
 
 	  This has to be enabled when the BLE controller connected is Zephyr
 	  open source controller.
+
+config BT_HCI_SETUP
+	bool
+	help
+	  Enable the HCI vendor-specific Setup function.
+
+	  This option has to be enabled when the BT Controller requires execution
+	  of the vendor-specific commands sequence to initialize the BT Controller
+	  before the BT Host executes a Reset sequence.
+
+	  The user should generally avoid changing it via menuconfig or in
+	  configuration files. This option are enabled by the vendor-specific
+	  HCI extension, where the Setup function is implemented.

include/drivers/bluetooth/hci_driver.h

@@ -185,6 +185,21 @@ struct bt_hci_driver {
 	 * @return 0 on success or negative error number on failure.
 	 */
 	int (*send)(struct net_buf *buf);
+
+#if defined(CONFIG_BT_HCI_SETUP) || defined(__DOXYGEN__)
+	/**
+	 * @brief HCI vendor-specific setup
+	 *
+	 * Executes vendor-specific commands sequence to initialize
+	 * BT Controller before BT Host executes Reset sequence.
+	 *
+	 * @note @kconfig{CONFIG_BT_HCI_SETUP} must be selected for this
+	 * field to be available.
+	 *
+	 * @return 0 on success or negative error number on failure.
+	 */
+	int (*setup)(void);
+#endif /* defined(CONFIG_BT_HCI_SETUP) || defined(__DOXYGEN__)*/
 };
 
 /**