Kernel boot fails when enabling sdmmc3 in kernel and u-boot dts

[SmithRay]

We are trying to bringup the Wi-Fi module connected over the sdmmc3 line with the STM32MP157F based custom board. 

But it seems, when enabling the sdmmc3 lines on the kernel and u-boot dts files, the kernel boot fails on "Waiting for Keymaster device" as seen in the logs below:

This issue occurs only when the sdmmc3 is enabled in the dts, otherwise the boot is successful.

Cannot see where to look for the error!