CONFIG_MTD_AMDSTD is not available for thedefaultarchitecture x86.
Result is shown for architecture cris
default or selected kernelversion does not have config value CONFIG_MTD_AMDSTD.
Result is shown for kernelversion 5.4.123

CONFIG_MTD_AMDSTD (not configurable)

modulename: amd_flash.ko

configname: CONFIG_MTD_AMDSTD

Linux Kernel Configuration
└─>MTD_AMDSTD
In linux kernel since version 2.6.12  
This option enables support for flash chips using AMD-compatible
commands, including some which are not CFI-compatible and hence
cannot be used with the CONFIG_MTD_CFI_AMDSTD option.

It also works on AMD compatible chips that do conform to CFI.

source code: