Only map front buffer if glamor acceleration is disabled (v2)

Otherwise the front buffer may not be accessible by the CPU, because Mesa
sets the AMDGPU_GEM_CREATE_NO_CPU_ACCESS flag for tiled buffers, because
accessing tiled buffers with the CPU makes little sense.

v2: Also handle Option "AccelMethod" "none"
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

src/amdgpu_kms.c

@@ -1431,7 +1431,8 @@ static Bool amdgpu_setup_kernel_mem(ScreenPtr pScreen)
 			return FALSE;
 		}
 
-		if (amdgpu_bo_map(pScrn, info->front_buffer)) {
+		if (!info->use_glamor &&
+		    amdgpu_bo_map(pScrn, info->front_buffer) != 0) {
 			ErrorF("Failed to map front buffer memory\n");
 			return FALSE;
 		}

src/drmmode_display.c

@@ -1741,7 +1741,7 @@ static Bool drmmode_xf86crtc_resize(ScrnInfoPtr scrn, int width, int height)
 		goto fail;
 	}
 
-	if (amdgpu_bo_map(scrn, info->front_buffer)) {
+	if (!info->use_glamor && amdgpu_bo_map(scrn, info->front_buffer) != 0) {
 		xf86DrvMsg(scrn->scrnIndex, X_ERROR,
 			   "Failed to map front buffer memory\n");
 		goto fail;