Enable xcompmgr with both full and fake KMS on all platforms

debian/changelog

@@ -1,3 +1,9 @@
+raspi-config (20210816) bullseye; urgency=medium
+
+  * Enable xcompmgr with full KMS as well as fKMS on all platforms
+
+ -- Simon Long <simon@raspberrypi.com>  Mon, 16 Aug 2021 14:02:06 +0100
+
 raspi-config (20210610) bullseye; urgency=medium
 
   * Remove redundant xcompmgr parameter

usr/lib/raspi-config/cmstart.sh

@@ -1,5 +1,5 @@
 #!/bin/sh
-if grep -q okay /proc/device-tree/soc/v3d@7ec00000/status 2> /dev/null || grep -q okay /proc/device-tree/soc/firmwarekms@7e600000/status 2> /dev/null ; then
+if grep -q okay /proc/device-tree/soc/v3d@7ec00000/status 2> /dev/null || grep -q okay /proc/device-tree/v3dbus/v3d@7ec04000/status 2> /dev/null || grep -q okay /proc/device-tree/soc/firmwarekms@7e600000/status 2> /dev/null ; then
     if ps ax | grep -v grep | grep -q openbox ; then
         exec xcompmgr -a
     fi