spdx.py: Add SPDXAnnotation Object

This is added to allow the create-spdx code to create annotations
that store values properly according to the SPDX Specification.

Initialy they will be used to track if a recipe is a native type.

(From OE-Core rev: 8db551bba619f3b3612c59270043148214a462cc)

Signed-off-by: Saul Wold <saul.wold@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/lib/oe/spdx.py

@@ -123,6 +123,12 @@ class SPDXObject(metaclass=MetaSPDXObject):
         raise KeyError("%r is not a valid SPDX property" % name)
 
 
+class SPDXAnnotation(SPDXObject):
+    annotationDate = _String()
+    annotationType = _String()
+    annotator = _String()
+    comment = _String()
+
 class SPDXChecksum(SPDXObject):
     algorithm = _String()
     checksumValue = _String()
@@ -164,6 +170,7 @@ class SPDXPackage(SPDXObject):
     packageVerificationCode = _Object(SPDXPackageVerificationCode)
     hasFiles = _StringList()
     packageFileName = _String()
+    annotations = _ObjectList(SPDXAnnotation)
 
 
 class SPDXFile(SPDXObject):