drm/qxl: add support for > 1 output

This adds support for a default of 4 heads, with a command line
parameter to change the default number.

It also overhauls the modesetting code to handle this case properly,
and send the correct things to the hardware at the right time.

Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/qxl/qxl_fb.c b/drivers/gpu/drm/qxl/qxl_fb.c
index 4b955b0..c08e128 100644
--- a/drivers/gpu/drm/qxl/qxl_fb.c
+++ b/drivers/gpu/drm/qxl/qxl_fb.c
@@ -538,7 +538,7 @@
 	qfbdev->helper.funcs = &qxl_fb_helper_funcs;
 
 	ret = drm_fb_helper_init(qdev->ddev, &qfbdev->helper,
-				 1 /* num_crtc - QXL supports just 1 */,
+				 qxl_num_crtc /* num_crtc - QXL supports just 1 */,
 				 QXLFB_CONN_LIMIT);
 	if (ret) {
 		kfree(qfbdev);