[PATCH 4.4 64/69] pwm: Unexport children before chip removal

4.4-stable review patch. If anyone has any objections, please let me know. -- From: David Hsu commit 0733424c9ba9f42242409d1ece780777272f7ea1 upstream. Exported pwm channels aren't removed before the pwmchip and are leaked. This results in invalid sysfs

[PATCH 4.4 64/69] pwm: Unexport children before chip removal

4.4-stable review patch. If anyone has any objections, please let me know. -- From: David Hsu commit 0733424c9ba9f42242409d1ece780777272f7ea1 upstream. Exported pwm channels aren't removed before the pwmchip and are leaked. This results in invalid sysfs files. This fix