Commit mt76: drop default eeprom file for mt7986-firmware (e3aa645b26) breaks eeprom loading for Mercusys MR90X v1. As a result WiFi is not working at all. This commit adds Mercusus MR90x to the caldata script (it works after the commit mentioned above). And we can safely drop "81_fix_eeprom" script as it's no longer required. Fixes:e3aa645b26Signed-off-by: Mikhail Zhilkin <csharper2005@gmail.com>