LF-2581-2 arm64: defconfig: add imx_v8_defconfig

Generated for LTS release by:
make ARCH=arm64 defconfig imx.config
make ARCH=arm64 savedefconfig
cp -avf defconfig arch/arm64/configs/imx_v8_defconfig

Based on commit: 547c7f50e3fc (next-nxp-20201028)

Plus items below to align with v5.4 release:
CONFIG_CPU_FREQ_GOV_SCHEDUTIL=y
CONFIG_MODVERSIONS=y
CONFIG_SND_SOC_IMX_PCM512X=y

And remove:
CONFIG_MXC_MLB150=y

Acked-by: Jason Liu <jason.hui.liu@nxp.com>
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>