Bluetooth: host: Update hci_init function to call setup function.

Updated hci_init function to call HCI vendor-specific Setup function
(bt_dev.drv->setup()) on beginning of HCI initialization.

This feature need 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>