meta: add search, replace strings to export2json

We want to be able to save relative paths so that we can relocate the
deploy dir images and kernels, yet still have qemu and testimage work
correctly.  This extends export2json with 2 named arguments so a
search/replace operation can be done to remove the leading path.

[YOCTO #11375]

(From OE-Core rev: 4829f1ebd89dc91860cf72fbbdc7b6bb0d5822bc)

Signed-off-by: brian avery <brian.avery@intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/lib/oe/data.py

@@ -17,7 +17,7 @@ def typed_value(key, d):
     except (TypeError, ValueError) as exc:
         bb.msg.fatal("Data", "%s: %s" % (key, str(exc)))
 
-def export2json(d, json_file, expand=True):
+def export2json(d, json_file, expand=True, searchString="",replaceString=""):
     data2export = {}
     keys2export = []
 
@@ -37,9 +37,11 @@ def export2json(d, json_file, expand=True):
 
     for key in keys2export:
         try:
-            data2export[key] = d.getVar(key, expand)
+            data2export[key] = d.getVar(key, expand).replace(searchString,replaceString)
         except bb.data_smart.ExpansionError:
             data2export[key] = ''
+        except AttributeError:
+            pass
 
     with open(json_file, "w") as f:
         json.dump(data2export, f, skipkeys=True, indent=4, sort_keys=True)