UPSTREAM: dt-bindings: rockchip-thermal: fix the misleading description

UPSTREAM: dt-bindings: rockchip-thermal: fix the misleading description

"rockchip,hw-tshut-temp", "rockchip,hw-tshut-mode" and
"rockchip,hw-tshut-polarity" are not a required properties
actually as the code could also work by loading the default
settings there. So it is apprently misleading, although we
prefer to get these from DT. And it seems we miss the 'rockchip,grf'
here which should also be an optional property.

Change-Id: I5ae62b7137f88da40475caec3b6d43a00219d85d
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Caesar Wang <wxt@rock-chips.com>
(cherry picked from git.kernel.org evalenti/linux-soc-thermal.git next
 commit 38e133ee6ea54bdfbe64c0e57bea4bc1e616c19a)