arm64: drop redundant "ARMv8" from Kconfig option title

All these platforms are ARMv8 or newer and choosing the platforms in
menuconfig is much easier if the titles start with something specific.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230120125722.270722-1-krzysztof.kozlowski@linaro.org


Signed-off-by: Arnd Bergmann <arnd@arndb.de>