hob: rework image output type setting

The preferences UI to set the image output type only supported setting a
single value whereas it's common practice, particularly for those making
use of the ADT, to set multiple values. This is also the default in Poky.

This reworked preferences UI dynamically generates check boxes for each
available image type and sets an appropriate string representing all image
types when checkboxes are toggled.

Includes fixes for [YOCTO #1273]

(Bitbake rev: f7f68847dd165f2ad0f39011db4ebfef3ae73f42)

Signed-off-by: Joshua Lock <josh@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/ui/hob.py

@@ -900,7 +900,8 @@ def main (server, eventHandler):
         # up to and including the space
         pmake = int(pmake.lstrip("-j "))
 
-    image_types = server.runCommand(["getVariable", "IMAGE_TYPES"])
+    selected_image_types = server.runCommand(["getVariable", "IMAGE_FSTYPES"])
+    all_image_types = server.runCommand(["getVariable", "IMAGE_TYPES"])
 
     pclasses = server.runCommand(["getVariable", "PACKAGE_CLASSES"]).split(" ")
     # NOTE: we're only supporting one value for PACKAGE_CLASSES being set
@@ -909,7 +910,7 @@ def main (server, eventHandler):
     pkg, sep, pclass = pclasses[0].rpartition("_")
 
     prefs = HobPrefs(configurator, handler, sdk_mach, distro, pclass, cpu_cnt,
-                     pmake, bbthread, image_types)
+                     pmake, bbthread, selected_image_types, all_image_types)
     layers = LayerEditor(configurator, None)
     window = MainWindow(taskmodel, handler, configurator, prefs, layers, mach)
     prefs.set_parent_window(window)