Fix runqemu by generating an ext4 image by default

Fix runqemu by generating an ext4 image by default

runqemu does not detect an ext4.xz , thus default to ext4.

Call it with:
  runqemu qemux86-64 kvm audio

Also due to the optimization levels for x86-64, adapt QB_CPU and QB_CPU_KVM.
For audiomanager to start up, sound needs to be enabled. QB_AUDIO_DRV and QB_AUDIO_OPT enable this.
Finally bump memory in runqemu to 2G.

For CI purposes, introduce a DISTRO_FEATURES flag 'AGLCI'.

v2: fix missing space in append
v3: qemuboot options fix
v4: QB_AUDIO_DRV defaults to alsa

Bug-AGL: SPEC-784

Change-Id: Ie9c9c2b7d8838b512f3f19b1e29952079039e0ab
Signed-off-by: Jan-Simon Möller <jsmoeller@linuxfoundation.org>
Reviewed-on: https://gerrit.automotivelinux.org/gerrit/10387
Tested-by: Jenkins Job builder account <agl-jobbuilder@automotivelinux.org>
ci-image-build: Jenkins Job builder account <agl-jobbuilder@automotivelinux.org>
ci-image-boot-test: Jenkins Job builder account <agl-jobbuilder@automotivelinux.org>