hwmon: (aspeed-pwm-tacho) make fan/pwm names start with index 1

Make fan and pwm names in sysfs start with index 1 in accordance to
Documentation/hwmon/sysfs-interface conventions.

Current implementation starts with index 0, making tools such as
sensors(1) skip the first fan.

Signed-off-by: Stefan Schaeckeler <sschaeck@cisco.com>
Fixes: 2d7a548a ("drivers: hwmon: Support for ASPEED PWM/Fan tach")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>