Beep is a target-independent software that can handle buzzers controlled by kmod-gpio-beeper.

This change is useful for some non-x86 enterprise APs and development boards
that have a buzzer connected to GPIO.

Compile-tested: ath79, ELECOM WAB-I1750-PS, 3fab4ac + device support patch
Run-tested: ath79, ELECOM WAB-I1750-PS, 3fab4ac + device support patch

Signed-off-by: Yanase Yuki <dev@zpc.sakura.ne.jp>

Signed-off-by: Yanase Yuki <dev@zpc.sakura.ne.jp>

This adds the beep utility, which allows users to control a pc speaker device.

Maintainer: me / @riptidewave93
Compile tested: x86/64, LEDE Reboot SNAPSHOT r2709-b7677f0 
Run tested: x86/64, LEDE Reboot SNAPSHOT r2709-b7677f0. Verify program works.
Signed-off-by: Chris Blake <chrisrblake93@gmail.com>