sanitycheck: don't require arch.ini blocks for every platform

If the arch ini file doesn't have a specific block for the platform,
just assume all defaults.

Change-Id: Id6ab1ede8936bdd6006a5c4fd2f9a4f6aaf42478
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
diff --git a/scripts/sanitycheck b/scripts/sanitycheck
index 10f5ba2..d05f3e3 100755
--- a/scripts/sanitycheck
+++ b/scripts/sanitycheck
@@ -831,7 +831,8 @@
         cp = self.cp
 
         if not cp.has_section(section):
-            raise ConfigurationError(self.filename, "Missing section '%s'" % section)
+            # Just fill it with defaults
+            cp.add_section(section)
 
         for k, v in cp.items(section):
             if k not in valid_keys: