i2c_software: Implementation of software i2c (#6141)

Signed-off-by: Alan.Ma from BigTreeTech <tech@biqu3d.com>

src/i2c_software.h

@@ -0,0 +1,13 @@
+#ifndef __I2C_SOFTWARE_H
+#define __I2C_SOFTWARE_H
+
+#include <stdint.h> // uint8_t
+
+struct i2c_software *i2c_software_oid_lookup(uint8_t oid);
+void i2c_software_write(struct i2c_software *sw_i2c
+                        , uint8_t write_len, uint8_t *write);
+void i2c_software_read(struct i2c_software *sw_i2c
+                       , uint8_t reg_len, uint8_t *reg
+                       , uint8_t read_len, uint8_t *read);
+
+#endif // i2c_software.h