support avr architecture based on ATMega32

1. IAR project, see TencentOS-tiny\board\ATMega32\IAR, both 4.12 and 7.20 is supplied.

board/ATMega32/BSP/include/uart.h

@@ -0,0 +1,13 @@
+#ifndef __USART_H_
+#define __USART_H_
+
+void uart_send_byte(char data);
+
+void uart_send_string(char *string);
+
+unsigned char uart_receive(void);
+
+void uart_init(unsigned int baudrate);
+
+#endif
+