arm64: defconfig: sync with savedefconfig

Sync the defconfig with savedefconfig as config options change/move over
time.

Generated with the following commands:
make defconfig
make savedefconfig
cp defconfig arch/arm64/configs/defconfig

Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Olof Johansson <olof@lixom.net>