commit 0d6aaffc upstream.

pwm attributes have well defined names, which should be used.

Cc: Vadim V. Vlasov <vvlasov@dev.rtsoft.ru>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>