Disabling audio on when running runqemu qemuarm

Added the change that prevented runqemu to throw
sound errors.

[YOCTO #3528]

(From OE-Core rev: 0ddcd2ce24f0cc65561e2d26c9d63048beedc40e)

Signed-off-by: Andrei Dinu <andrei.adrianx.dinu@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/runqemu-internal

@@ -302,6 +302,7 @@ fi
 if [ "$MACHINE" = "qemuarm" -o "$MACHINE" = "qemuarmv6" -o "$MACHINE" = "qemuarmv7" ]; then
     QEMU=qemu-system-arm
     MACHINE_SUBTYPE=versatilepb
+    export QEMU_AUDIO_DRV="none"
     QEMU_UI_OPTIONS="$QEMU_UI_OPTIONS"
     # QEMU_UI_OPTIONS="$QEMU_UI_OPTIONS -force-pointer"
     if [ "$FSTYPE" = "ext3" -o "$FSTYPE" = "btrfs" ]; then