bt: compile hci_uart as module [3/4]

bt: compile hci_uart as module [3/4]

PD#150522: compile hci_uart as module

    meson64_smarthome_defconfig:

    CONFIG_BT_HCIUART=m
    CONFIG_BT_HCIUART_QCA=y

1. realtek bt has its own hci_uart driver
   so we need compile both hci_uart driver
   as module

2. add hciuart_qca support, for we need qualcomm
   bt for bluez later

Change-Id: Icffbb66623a5e28803a4f26bb3523f79cae91bc3
Signed-off-by: Weiguang Ruan <Weiguang.ruan@amlogic.com>