srf04.c: add maxbotix ultrasonic sensors

add Maxbotix LV ultrasonic sensor types mb1000, mb1010, mb1020, mb1030
and mb1040

add a configuration struct with the different trigger pulse lengths

Signed-off-by: Andreas Klinger <ak@it-klinger.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
1 file changed