arm64/sve: Make sysctl interface for SVE reusable by SME

mainline inclusion
from mainline-v5.17-rc1
commit 97bcbee4
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8E73O
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=97bcbee404e386195614b58e98ab2e7eddd89a5c



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The vector length configuration for SME is very similar to that for SVE
so in order to allow reuse refactor the SVE configuration so that it takes
the vector type from the struct ctl_table. Since there's no dedicated space
for this we repurpose the extra1 field to store the vector type, this is
otherwise unused for integer sysctls.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211210184133.320748-2-broonie@kernel.org


Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Wang ShaoBo <bobo.shaobowang@huawei.com>