Updated the magic techfile to correct a few errors and extend the
support for SRAM cells (to read and extract;  no attempt to try
to write an SRAM cell correctly).
diff --git a/common/soc_floorplanner.py b/common/soc_floorplanner.py
index 31c6b8f..18a8995 100755
--- a/common/soc_floorplanner.py
+++ b/common/soc_floorplanner.py
@@ -1258,6 +1258,7 @@
                 print('load ' + magfile + ' -force', file=ofile)
             else:
                 print('load ' + module + ' -force', file=ofile)
+            print('select top cell', file=ofile)
             print('lef write -hide', file=ofile)
             print('quit', file=ofile)