Here kszaq, dmesg output using gxl_p212_1g_slowemmc.dtb and the LibreELEC-S905.arm-8.2-devel-20171213185420-r26471-gc91652d.tar build above.
Still no /dev/sys
Your box does not have eMMC chip, this device tree won't solve the issue. Like I said before, I cannot fix closed-source NAND driver.