ARM: dts: rockchip: Fix thermal sensor cells o rk322x

The number of cells to be used with a thermal sensor specifier
must be "1". Fix this.

Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20210506175514.168365-2-ezequiel@collabora.com