default or selected kernelversion does not have config value CONFIG_PINCTRL_MTK_COMMON.
Result is shown for kernelversion 5.4.229

CONFIG_PINCTRL_MTK_COMMON (not configurable)

modulename: pinctrl-mtk-common.ko

configname: CONFIG_PINCTRL_MTK_COMMON

Linux Kernel Configuration
└─>Device Drivers
└─>Pin controllers
└─>PINCTRL_MTK_COMMON
In linux kernel since version 4.1 (release Date: 2015-06-21)  
source code:
drivers/pinctrl/mediatek/pinctrl-mtk-common.c

depends
CONFIG_OF
CONFIG_PINCTRL
CONFIG_ARCH_MEDIATEK or CONFIG_COMPILE_TEST