docs: hwmon: aspeed-pwm-tacho: convert to ReST format

Convert aspeed-pwm-tacho to ReST format, in order to allow it to
be parsed by Sphinx.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Documentation/hwmon/aspeed-pwm-tacho

@@ -15,8 +15,10 @@ controller supports up to 16 tachometer inputs.
 
 The driver provides the following sensor accesses in sysfs:
 
+=============== ======= =====================================================
 fanX_input	ro	provide current fan rotation value in RPM as reported
 			by the fan to the device.
 
 pwmX		rw	get or set PWM fan control value. This is an integer
 			value between 0(off) and 255(full speed).
+=============== ======= =====================================================