AP_ExternalAHRS/AP_Periph: fix build errors from missing macro defaults and absent DroneCAN guard - #2

AP_ExternalAHRS/AP_Periph: fix build errors from missing macro defaults and absent DroneCAN guard#2

huangfuluya with Copilot wants to merge 10 commits into

pr_apm47_can_ahrshuangfuluya/ardupilot:pr_apm47_can_ahrsfrom

copilot/use-pixhawk6x-as-external-ahrshuangfuluya/ardupilot:copilot/use-pixhawk6x-as-external-ahrsCopy head branch name to clipboard