Bluetooth: tester: Add project configuration for BR

Set following configuration by default,
CONFIG_BT_CLASSIC=y
CONFIG_BT_CENTRAL=y
CONFIG_BT_PERIPHERAL=y
CONFIG_BT_SMP=y
CONFIG_BT_L2CAP_DYNAMIC_CHANNEL=y
CONFIG_BT_PAGE_TIMEOUT=0xFFFF

When building the project, the argument `--extra-conf prj_br.conf`
needs to be appended for BR.

Signed-off-by: Lyle Zhu <lyle.zhu@nxp.com>