thermal: rcar_thermal: add r8a77995 support

Add support for R-Car D3 (r8a77995) thermal sensor.

Signed-off-by: Yoshihiro Kaneko <ykaneko0929@gmail.com>
Tested-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>