gbm: Use libkms to replace DRI cursor images

gbm: Use libkms to replace DRI cursor images

Uses libkms instead of dri image cursor. Since this is the only user of the
DRI cursor and write interface we can remove cursor surfaces entirely from
the DRI interface and as a consequence also from the Gallium interface as
well. Tho to make everybody happy with this it would probably should add a
kms_bo_write function, but that is probably wise in anyways.

The only downside is that it adds a dependancy on libkms, this could how ever
be replaced with the dumb_bo drm ioctl interface.

Tested-by: Scott Moreau <oreaus@gmail.com>
Signed-off-by: Jakob Bornecrantz <jakob@vmware.com>