HCSR04 driver: rewrite and correct style
HCSR04 driver:remove STM32F1XX GPIO Enable the peripheral clock 'PIOS_SYS_Init(); make this'
HCSR04 driver:reduce capture channels to one
     FlyingF3:board_hw_defs correct pios_tim_servoport_rcvrport_pins - defined(PIOS_INCLUDE_HCSR04)