svga: invalidate new surface before it is bound to a render target view

svga: invalidate new surface before it is bound to a render target view

Invalidate a "new" surface before it is bound to a render target view or
depth stencil view in order to avoid the unnecessary host side copy
of the surface data before it is rendered to.
Note that, recycled surface is already invalidated before it is reused.

Reviewed-by: Brian Paul <brianp@vmware.com>