Add buzzer test source code

guowenxue

2025-12-17 fe7aebb0fa469c98f4ac3bc52874738f84edb515

../alientek-imx6ull-v20/uboot-imx-lf-6.1.36-2.1.0.patch does not exist in tree 1c47392435daa10bfa85e782759c0dcc6305d678