vmwgfx: Reinstate the update_layout ioctl

We need to redefine a connector as "connected" if it matches a window
in the host preferred GUI layout.
Otherwise "smart" window managers would turn on Xorg outputs that we don't
want to be on.

This reinstates the update_layout and adds the following information to
the modesetting system.
a) Connection status <-> Equivalent to real hardware connection status
b) Preferred mode <-> Equivalent to real hardware reading EDID
c) Host window position <-> Equivalent to a real hardware scanout address
dynamic register.

It should be noted that there is no assumption here about what should be
displayed and where. Only how to access the host windows.

This also bumps minor to signal availability of the new IOCTL.

Based on code originally written by Jakob Bornecrantz

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>