RUI UART Receive

void rui_uart_recv(RUI_UART_DEF uart_def, uint8_t *pdata, uint16_t len)

@brief	This API is used to receive data from UART.
@return	NULL
@param	RUI_UART_DEF uart_def : the instance of UART. uint8_t *pdata : the pointer of data. uint16_t len : the length of data. This value is always 1.
@module	RAK811, RAK4200, RAK4400, RAK4600, and RAK5010.