Makefile: add all target to compile and download.

firmware/Makefile

@@ -37,6 +37,9 @@ help:
 	@echo "       ISP=${ISP}"
 	@echo "       PORT=${PORT}"
 
+all: main.hex
+	make flash
+
 COMPILE = avr-gcc -Wall -O2 -Iusbdrv -I. -mmcu=$(TARGET) # -DDEBUG_LEVEL=2
 
 OBJECTS = usbdrv/usbdrv.o usbdrv/usbdrvasm.o usbdrv/oddebug.o isp.o clock.o tpi.o main.o