Update to 4.0-rc4.
    
    - Config changes:
      - ppc/ppc64/ppc64le/armv7hl/arm64:
        - OF_OVERLAY=y (no functional change, the option was introduced to
                        allow disabling of previously builtin behavior)
        - CONFIG_OF_RECONFIG_NOTIFIER_ERROR_INJECT=m
      - i386:
        - OF_OVERLAY=n