rockchip: enable rockchip-thermal

Enable the rockchip-thermal driver to allow reading the temperature of
the SoC.

Tested on NanoPi R2S

Signed-off-by: David Bauer <[email protected]>

target/linux/rockchip/armv8/config-5.4

@@ -387,7 +387,7 @@ CONFIG_ROCKCHIP_IOMMU=y
 CONFIG_ROCKCHIP_MBOX=y
 CONFIG_ROCKCHIP_PHY=y
 CONFIG_ROCKCHIP_PM_DOMAINS=y
-# CONFIG_ROCKCHIP_THERMAL is not set
+CONFIG_ROCKCHIP_THERMAL=y
 CONFIG_ROCKCHIP_TIMER=y
 CONFIG_RSEQ=y
 CONFIG_RTC_CLASS=y