[FS#1496] can not enable /dev/mem by "make kernel_menuconfig"

[LEDE Bugs]

The following task has a new comment added:

FS#1496 - can not enable /dev/mem by "make kernel_menuconfig"
User who did this - Matthias Schiffer (NeoRaider)

----------
Did you try enabling CONFIG_KERNEL_DEVMEM in the OpenWrt toplevel .config? ("Global build settings" -> "Kernel build options" -> "/dev/mem virtual device support" in `make menuconfig`)? Settings in toplevel .config take precedence over kernel .config.
----------

More information can be found at the following URL:
https://bugs.openwrt.org/index.php?do=details&task_id=1496#comment4591