After DTS sync with Linux kernel 5.8 this patch was included:
"ARM: dts: Move am33xx and am43xx mmc nodes to sdhci-omap driver"
Current will not load any driver for MMC and not mount the rootfs.
Simple patch add "ti,am335-sdhci" to compability strings in ti_sdhci.c
Reported by: Poul-Henning Kamp