connman: disable BackgroundScanning.

We dont use it anyway and it makes wifi a little unstable.
At least on RPi.
Merge pull request #2054 from jenkins101/connman-bgscan

connman: disable BackgroundScanning.
projects/ATV/xbmc: set some default options

Signed-off-by: Stephan Raue <stephan@openelec.tv>
Merge remote-tracking branch 'upstream/master'