sunxi: add SND_SIMPLE_CARD to kernel config

sunxi: add SND_SIMPLE_CARD to kernel config

This is required to expose an ALSA card for quite some boards:

$ git grep -l simple-audio-card \
	arch/arm/boot/dts/sun?i* \
	arch/arm64/boot/dts/allwinner/*

arch/arm/boot/dts/sun4i-a10-a1000.dts
arch/arm/boot/dts/sun5i-gr8-evb.dts
arch/arm/boot/dts/sun6i-a31-i7.dts
arch/arm/boot/dts/sun6i-a31s-sina31s.dts
arch/arm/boot/dts/sun7i-a20-cubietruck.dts
arch/arm/boot/dts/sun7i-a20-itead-ibox.dts
arch/arm/boot/dts/sun8i-a33-olinuxino.dts
arch/arm/boot/dts/sun8i-a33.dtsi
arch/arm/boot/dts/sun8i-a83t-cubietruck-plus.dts
arch/arm/boot/dts/sun8i-h3-beelink-x2.dts
arch/arm64/boot/dts/allwinner/sun50i-a64-bananapi-m64.dts
arch/arm64/boot/dts/allwinner/sun50i-a64-orangepi-win.dts
arch/arm64/boot/dts/allwinner/sun50i-a64-pine64.dts
arch/arm64/boot/dts/allwinner/sun50i-a64-pinebook.dts
arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi
arch/arm64/boot/dts/allwinner/sun50i-a64-pinetab.dts
arch/arm64/boot/dts/allwinner/sun50i-a64-sopine-baseboard.dts
arch/arm64/boot/dts/allwinner/sun50i-a64-teres-i.dts
arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi
arch/arm64/boot/dts/allwinner/sun50i-h6-beelink-gs1.dts

The compressed 32bit kernel increases less than 1K:
Before: 3230768 zImage
After:  3231664 zImage

Signed-off-by: Andre Heider <a.heider@gmail.com>