conf/machine/x86-base: use wic instead of live
Use wic instead of the live/hddimg filesystem type for x86 machines, as it
produces better filesystems and doesn't have a hard limit of 4GB.
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>