Now I looked at this problem... and proximity gpio-switch is for unknown reason disabled in kernel. I looked at diff between kp52 and kp53 and there is nothing which can disable gpio-switch. So problem must be somewhere in userspace. Maybe CSSU or U-Boot? Maybe other application?

This sysfs can enable or disable proximity gpio-switch:
$ cat /sys/devices/platform/gpio-switch/proximity/disable

And this command enable it (until reboot):
$ echo 0 > /sys/devices/platform/gpio-switch/proximity/disable