hwmon: (dell-smm) Remove unnecessary includes

sched.h and io.h are not used anywhere in dell-smm-hwmon.c.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20210926221044.14327-3-W_Armin@gmx.de


Signed-off-by: Guenter Roeck <linux@roeck-us.net>