drm/nouveau/hwmon: use simplified HWMON_CHANNEL_INFO macro

This makes the code look cleaner and easier to read.

Signed-off-by: Beniamin Sandu <beniaminsandu@gmail.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220815104028.381271-1-beniaminsandu@gmail.com