beagleblack: tune configs to be similar with other boards

Signed-off-by: Fatih Aşıcı <fatih.asici@gmail.com>
beagleblack: use EABIHF

Signed-off-by: Fatih Aşıcı <fatih.asici@gmail.com>
beagleblack: use a linaro toolchain without multi-arch support

Signed-off-by: Fatih Aşıcı <fatih.asici@gmail.com>