usb: hid: allow boot interface Protocol Code to be set per device

Kconfig option USB_HID_PROTOCOL_CODE does not allow to set
boot interface protocol code for specific HID device but
only to set the same value for all device.
Add new API function to allow the application to set
Protocol Code per device. Deprecate USB_HID_PROTOCOL_CODE option.

Fixes: #32778

Signed-off-by: Johann Fischer <johann.fischer@nordicsemi.no>