image.bbclass: Sorted ctypes to avoid basehash error
When selected multiple subimages a similar error could happend:
Variable do_image_cpio[subimages] value changed \
from 'cpio.gz.u-boot cpio.gz' to 'cpio.gz cpio.gz.u-boot'
To avoid this, 'ctypes' should be sorted at 'gen_conversion_cmds'.
This garantee that 'CONVERSION_CMD_xxx' are always written in tha same
order and consequently 'do_image_cpio' have the same hash.
Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
