Example for using PWM in mini2440

基于mini2440开发板的linux下s3c2440的pwm驱动程序，实际测试验证，程序可正常运行，方便移植到其他开发平台。-Under mini2440 development board based on linux s3c2440 pwm driver, actual test, the program can run normally, easily ported to other development platforms.