arm64: defconfig: cleanup the defconfig

When doing:
   make defconfig
   make savedefconfig

...without making any changes, the newly saved defconfig does
not match arch/arm64/configs/defconfig, and the diff looks
like:

$ diff defconfig arch/arm64/configs/defconfig
3a4
> CONFIG_FHANDLE=y

Clean that up by committing the output of savedefconfig.

Signed-off-by: Stuart Yoder <stuart.yoder@nxp.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>