Initialize drmmode_crtc dpms_mode to DPMSModeOff

This disables query of disabled pipes for drmWaitVBlank on X start
Signed-off-by: Mykola Lysenko <Mykola.Lysenko@amd.com>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
(cherry picked from commit 4eb9cedc)

src/drmmode_display.c

@@ -993,6 +993,7 @@ drmmode_crtc_init(ScrnInfoPtr pScrn, drmmode_ptr drmmode, drmModeResPtr mode_res
 	drmmode_crtc->mode_crtc =
 	    drmModeGetCrtc(pAMDGPUEnt->fd, mode_res->crtcs[num]);
 	drmmode_crtc->drmmode = drmmode;
+	drmmode_crtc->dpms_mode = DPMSModeOff;
 	crtc->driver_private = drmmode_crtc;
 	drmmode_crtc_hw_id(crtc);