linux: dont let cpupower-start.service fail if setting up to performance fails
llvm: disable zlib support in hostbuild, to prevent a build error if zlib-devel is not installed on host system

Signed-off-by: Stephan Raue <stephan@openelec.tv>
Merge branch 'master' of github.com:OpenELEC/OpenELEC.tv
busybox: start debugshell on "tty" boot parameter
busybox-initramfs: remove systemd debug args

^^ fixes long boot delay with debugging enabled
Merge branch 'master' of github.com:OpenELEC/OpenELEC.tv
projects/ATV: switch to more generic compiler optimizations

Signed-off-by: Stephan Raue <stephan@openelec.tv>
xbmc: update to xbmc-12.2-9714e7e

Signed-off-by: Stephan Raue <stephan@openelec.tv>