@jsulm Thanks I will follow the link.
Not sure about Qt 5.10, but Qt 5.12 have support for arm64-v8a target. You will need to build two APK files, one for armeabi-v7a, and one for arm64-v8a, with different versionCode values in manifest, and then just publish both in the same release.
AFAIK, the BPI is very close to the Raspberry Pi, you should take a look at this wiki entry.
By the way, why are you trying to build an outdated version of Qt ? The current LTS is the 5.9 series with 5.12 around the corner.