ARM: sun5i: Fix typo in trip point temperature

Set cpu_alert0 temperature to 85°C instead of 850°C.

Fixes: 32a5d2d1 ("ARM: dts: sun5i: Add cpu thermal zones to dtsi")
Signed-off-by: Hugo Grostabussiat <bonstra@bonstra.fr.eu.org>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>