This expands on the previous commit, exporting the fan RPM via hwmon.

This will look something like the following when using the "sensors"
command from lm_sensors:

toshiba_acpi_sensors-acpi-0
Adapter: ACPI interface
fan1:           0 RPM
Signed-off-by: Arvid Norlander <lkml@vorpal.se>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20220902174018.1720029-3-lkml@vorpal.seReviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>