config.conf: Reenable arm64 configs
    
    - config: Update to 6.4-rc5:
      * this includes lowering the ARCH_FORCE_MAX_ORDER by one given the
        change of definition in mainline commit 23baf831a32c
        ("mm, treewide: redefine MAX_ORDER sanely")
      * config change from x86_64 adopted for arm64. Enabled all erratas,
        rest compile as modules