Add Bluetooth support

[xbgmsharp]

There is no bluetooth interface on 4.14.11.
Install:

apt-get install bluez bluez-utils

Enable interface:

hciconfig hci0 up

[frank-w]

i had only tested wifi-AP after merging the combo-device-driver...there are also Problems with BT on 4.4:

http://forum.banana-pi.org/t/bpi-r2-new-image-ubuntu-16-04-v1-2-1-bt-and-wifi-ap-mode-are-working-fine-2017-11-27/4291/16

currently there is much work on other things so i will accept patches but do not work on BT now

[frank-w]

added this patch:
BPI-SINOVOIP/BPI-R2-bsp@3823964
and the BT-Options to the debug-branch

can you please test if BT now works?

[frank-w]

debug merged to main

bt works like in 4.4
occasionally hangs and bluetoothd does not work

[frank-w]

BT is actually not build in...

obj-$(CONFIG_MTK_COMBO_BT_HCI) += bt/

is missing in drivers/misc/mediatek/connectivity/Makefile

edit: bt-folder does not exist also in 4.4

just for reference:
http://forum.banana-pi.org/t/kernel-bluetouh-module/4592/17
BPI-SINOVOIP/BPI-R2-bsp@6b9512b

[xbgmsharp]

Kernel config to activate BT:

$ grep BT .config | grep -v '#'
CONFIG_BT=y
CONFIG_BT_BREDR=y
CONFIG_BT_HS=y
CONFIG_BT_LE=y
CONFIG_BT_DEBUGFS=y
CONFIG_MTK_BTIF=y
CONFIG_MTK_COMBO_BT=y
CONFIG_MTK_COMBO_BT_HCI=y

[frank-w]

added that to branch "debug_bt"