thermal: rcar: enable CPCTL to use hardware TSC deciding

If CPCTL was 1 on R-Car thermal, the thermal comparator offset
is automatically decided by hardware.
And this CPCTL is the conditions which validate interrupt.
This patch enabled CPCTL.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>