Auto mouse layer doesn't work if the ball on secondary

[koron]

This may be caused by "pointing device auto mouse" feature not assuming split keyboard.

[koron]

This was a mistaken observation by me. So this is invalid.

What's happened…

• AML feature is disabled by default. The default here is the state in which the EEPROM is cleared.
• I was using the right keyboard with ball when reviewing and testing AML feature. (#508)
• At that time, AML was enabled and the state was persisted in EEPROM.
• I tried to use left keyboard as primary
• The EEPROM on the left keyboard was empty.
• So I mistakenly observed that AMI did not work.

Additionally, I confirmed that if I clear the EEPROM on the right keyboard, AML is disabled by default. I would have noticed it sooner if I had checked the OLED properly. AML status is displayed on the OLED.