hwmon: (pmbus) fix a typo in Kconfig SENSORS_IR35221 option

Fix a typo in SENSORS_IR35221 option: module name should be "ir35221"
instead of "ir35521".

Fixes: 8991ebd9 ("hwmon: (pmbus) Add client driver for IR35221")

Cc: Samuel Mendoza-Jonas <sam@mendozajonas.com>
Signed-off-by: Tao Ren <rentao.bupt@gmail.com>
Link: https://lore.kernel.org/r/20200702221349.18139-1-rentao.bupt@gmail.com


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