This patch adds vblank interrupt support to atyfb. The added features are 
FB_ACTIVATE_VBL flag for panning and FBIO_WAITFORVSYNC ioctl.

The code is basically copied from matroxfb. I've tested it on two laptops 
(Mobility and LT Pro) using DirectFB.

-- 
Ville Syrjälä
syrjala@sci.fi
http://www.sci.fi/~syrjala/