TI中文支持网CC2640 几路PWM，软件中看到是8路，datasheet看到是四路
但是LED_WHITE和LED_BLUE之间有干扰，灯老闪烁，T咋回事
#define Board_PWMPIN0 LED_WHITE_PWM//PIN_UNASSIGNED
#define Board_PWMPIN1 LED_BLUE//PIN_UNASSIGNED
#define Board_PWMPIN2 LED_RED//PIN_UNASSIGNED
#define Board_PWMPIN3 PIN_UNASSIGNED
#define Board_PWMPIN4 PIN_UNASSIGNED
#define Board_PWMPIN5 PIN_UNASSIGNED
#define Board_PWMPIN6 PIN_UNASSIGNED
#define Board_PWMPIN7 PIN_UNASSIGNED
HG：
http://www.ti.com.cn/product/cn/CC2640/datasheet/abstract#SWRS1582549
四个通用定时器模块（8 × 16 位或 4 × 32 位，均采用脉宽调制 (PWM)）
