linux-yocto/5.15: fix arm defconfig warnings

Integrating the following commit(s) to linux-yocto/5.15:

    02bf23d26bc4 arm64: defconfig: cleanup config options
    05914e2c87e5 arm: defconfig: drop unused POWER_AVS option

Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>