ARM: dts: rockchip: override thermal settings on veyron-speedy

According to a commit on the ChromeOS kernel, the temperature of the Speedy
surface is over skin temperature spec. So adjust the thermal settings
to mimic the ChromeOS tree to stay within these spec limits.

Signed-off-by: Heiko Stuebner <heiko.stuebner@collabora.com>
Reviewed-by: Caesar Wang <wxt@rock-chips.com>