main/linux-lts (aarch64) Enable drivers for Marvell Espressobin
https://wiki.alpinelinux.org/wiki/Alpine_on_ARM lists armada-3720-espressobin as one of the supported targets, however, some relevant device drivers are missing from lts.aarch64.config
CONFIG_MVNETA=m - for the ethernet interface
CONFIG_REGULATOR_GPIO=m - for CD GPIO pins control by the SDHCI host (a microSD card isn't detected without it)
CONFIG_CRYPTO_DEV_SAFEXCEL=m - for the embedded SafeXcel-IP-97 crypto accelerator (AES, hash/HMAC)
CONFIG_TURRIS_MOX_RWTM=m - for the embedded hardware RNG