platform/x86: system76: constify pointers to hwmon_channel_info

Statically allocated array of pointers to hwmon_channel_info can be made
const for safety.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230511175627.282246-3-krzysztof.kozlowski@linaro.org


Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>