default or selected kernelversion does not have config value CONFIG_PINCTRL_IMX21.
Result is shown for kernelversion 6.9.9
i.MX21 pinctrl driver
modulename: pinctrl-imx21.ko
configname: CONFIG_PINCTRL_IMX21
Linux Kernel Configuration
└─>Device Drivers
└─>Pin controllers
└─>i.MX21 pinctrl driver
In linux kernel since version 3.18 (release Date: 2014-12-07)
Say Y here to enable the i.MX21 pinctrl driver