thermal: rockchip: handle the power sequence for tsadc controller

This adds the grf property to handle the tsadc power sequence on
rockchip some SoCs.

Verified on rk3399 can work with this patch on now.

while true; do grep "" /sys/class/thermal/thermal_zone[0-1]/temp
sleep .5; done
/sys/class/thermal/thermal_zone0/temp:40555
/sys/class/thermal/thermal_zone1/temp:41111
/sys/class/thermal/thermal_zone0/temp:40555
/sys/class/thermal/thermal_zone1/temp:41111
/sys/class/thermal/thermal_zone0/temp:40555
/sys/class/thermal/thermal_zone1/temp:41666
/sys/class/thermal/thermal_zone0/temp:40555
/sys/class/thermal/thermal_zone1/temp:41111
/sys/class/thermal/thermal_zone0/temp:40555
/sys/class/thermal/thermal_zone1/temp:41111
/sys/class/thermal/thermal_zone0/temp:40555

Signed-off-by: Caesar Wang <wxt@rock-chips.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>