hwmon: (oxp-sensors) Fix typo in driver documentation

RMP -> RPM
Signed-off-by: Cryolitia PukNgae <Cryolitia@gmail.com>
Link: https://lore.kernel.org/r/20240726-typo-v1-1-3ca3f07f93e9@gmail.comSigned-off-by: Guenter Roeck <linux@roeck-us.net>

Documentation/hwmon/oxp-sensors.rst

@@ -52,7 +52,7 @@ Sysfs entries
 The following attributes are supported:
 
 fan1_input
-  Read Only. Reads current fan RMP.
+  Read Only. Reads current fan RPM.
 
 pwm1_enable
   Read Write. Enable manual fan control. Write "1" to set to manual, write "0"