default or selected kernelversion does not have config value CONFIG_MFD_SH_MOBILE_SDHI.
Result is shown for kernelversion 5.4.69

Support for SuperH Mobile SDHI

modulename: sh_mobile_sdhi.ko

configname: CONFIG_MFD_SH_MOBILE_SDHI

Linux Kernel Configuration
└─>Device Drivers
└─>Multifunction device drivers
└─>Support for SuperH Mobile SDHI
In linux kernel since version 2.6.33 (release Date: 2010-02-24)  
This driver supports the SDHI hardware block found in many
SuperH Mobile SoCs.

source code:
drivers/mfd/sh_mobile_sdhi.c