SMP_Encrypt() function

* Function SMP_Encrypt * Description This function is called to encrypt the data with the specified * key * Parameters: key - Pointer to key key[0] conatins the MSB * key_len - key length * plain_text - Pointer to data to be encrypted * plain_text[0] conatins the MSB * pt_len - plain text length * p_out - output of the encrypted texts * Returns Boolean - request is successful