Recent versions of GDB seem to require 'make install' to find their
Python bits. Given that this is not really an option, check the
usual suspects, too.

Change-Id: I5217c0184681d4a86992fe0b8989498843b26cea
Reviewed-by: David Schulz <david.schulz@digia.com>
Reviewed-by: hjk <hjk121@nokiamail.com>