drm-backend: remove log that advertises universal planes support

There's a log that advertises support for universal planes. That
can make users think there's something wrong with Weston or their
systems when universal planes are not supported, but that's not
the case. Remove this log from the code.

Signed-off-by: Leandro Ribeiro <leandro.ribeiro@collabora.com>

libweston/backend-drm/kms.c

@@ -1463,8 +1463,6 @@ init_kms_caps(struct drm_backend *b)
 		ret = drmSetClientCap(b->drm.fd, DRM_CLIENT_CAP_UNIVERSAL_PLANES, 1);
 		b->universal_planes = (ret == 0);
 	}
-	weston_log("DRM: %s universal planes\n",
-		   b->universal_planes ? "supports" : "does not support");
 
 	if (b->universal_planes && !getenv("WESTON_DISABLE_ATOMIC")) {
 		ret = drmGetCap(b->drm.fd, DRM_CAP_CRTC_IN_VBLANK_EVENT, &cap);