Prince Frédéric Prinz von Anhalt Wants Grandkids ASAP, Rushes Adopted Son

Prince Frédéric Prinz von Anhalt knows he isn't getting any younger, and wants some grandkids from his adopted son ... fast! We got the Prince -- widower of Zsa Zsa Gabor -- leaving Wally's in Bev Hills ... out with his newly-adopted son,…