dt-bindings: hwmon: isl68137: Add compatible strings for RAA228942 and RAA228943

dt-bindings: hwmon: isl68137: Add compatible strings for RAA228942 and RAA228943

RAA228942 and RAA228943 are Renesas digital dual-output
16-phase (X+Y <= 16) PWM controllers with 2-rail non-TC
driver configuration. At the PMBus hwmon interface level,
they are compatible with existing 2-rail non-TC controllers
and use renesas,raa228244 as fallback compatible

Signed-off-by: Dawei Liu <dawei.liu.jy@renesas.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260325090208.857-2-dawei.liu.jy@renesas.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>