CONFIG_SOC_MT7620 is not available for the selected architecture x86.
Result is shown for architecture mips

MT7620

modulename: mt7620.ko

and/or

pci-mt7620.ko

configname: CONFIG_SOC_MT7620

Ralink SoC selection
└─>MT7620
In linux kernel since version 3.1 (release Date: 2011-10-24)
source code:
arch/mips/ralink/mt7620.c
selects
CONFIG_HW_HAS_PCI
CONFIG_CPU_MIPSR2_IRQ_VI
CONFIG_HAVE_PCI

is selected by
CONFIG_PINCTRL_MT7620