correction in v2.07b link

Signed-off-by: Toshaan Bharvani <toshaan@vantosh.com>

data/specifications/powerisa207.yaml

@@ -5,5 +5,5 @@ versions:
     description: "Initial release."
   - number: "2.07b"
     date: "2017-03-29"
-    download: "https://ibm.ent.box.com/s/1hzcwkwf8rbju5h9iyf44wm94amnlcrv"
     description: "Update specification."
+    download: "https://ibm.ent.box.com/s/jd5w15gz301s5b5dt375mshpq9c3lh4u"