openeuler_defconfig: enable SME for arm64 by default

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8E73O



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Set the following configuration to enable SME for arm64 by
default.

CONFIG_ARM64_SME=y

Signed-off-by: Wang ShaoBo <bobo.shaobowang@huawei.com>