meta-samsung: linux-samsung-tuna: enable wifi P2P support

Signed-off-by: Simon Busch <morphis@gravedo.de>
meta-android: chroot-script: separate common init script and machine settings

* we should try to minimize the need to have a init script per machine but enabled the
  machine layers to configure the required bits in a separate configuration file

Signed-off-by: Simon Busch <morphis@gravedo.de>
meta-android: chroot-script: add possiblity to boot from system partition

Signed-off-by: Simon Busch <morphis@gravedo.de>