Bluetooth: btrtl: Add btrealtek data struct

This patch adds a data structure for btrealtek object, and the
definition of vendor behavior flags. It also adds macros to set/test/get
the flags.

Signed-off-by: Hilda Wu <hildawu@realtek.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>