media: renesas: vsp1: Fix NULL pointer deref on module unload

In the Linux kernel, the following vulnerability has been resolved: media: renesas: vsp1: Fix NULL pointer deref on module unload When unloading the module on gen 4, we hit a NULL pointer dereference. This is caused by the cleanup code calling vsp1_drm_cleanup() where it should be calling vsp1_vspx_cleanup(). Fix this by checking the IP version and calling the drm or vspx function accordingly, the same way as the init code does.