优化模拟i2c时序逻辑，使模拟I2C时序更加接近设定的延迟时间 模拟I2C的IO翻转时间单位改为ns，使I2C通讯速率可调节度更准确

components/drivers/include/drivers/i2c-bit-ops.h

@@ -11,6 +11,9 @@
 #ifndef __I2C_BIT_OPS_H__
 #define __I2C_BIT_OPS_H__
 
+#include <rtdef.h>
+#include <rtdevice.h>
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -23,9 +26,9 @@ struct rt_i2c_bit_ops
     rt_int32_t (*get_sda)(void *data);
     rt_int32_t (*get_scl)(void *data);
 
-    void (*udelay)(rt_uint32_t us);
+    void (*ndelay)(rt_uint32_t us);
 
-    rt_uint32_t delay_us;  /* scl and sda line delay */
+    rt_uint32_t delay_ns;  /* scl and sda line delay */
     rt_uint32_t timeout;   /* in tick */
 };