Porting Test Ver.

* I don't know it's have correct Value.
* I guess led, 7segment's register value and source is Invalid.

* List of Changed.
 - SLOS\build\obj\linker.dat
 - SLOS\build\obj\makefile
 - SLOS\build\src\e7t\init.s
 - SLOS\build\src\e7t\pcb.s
 - SLOS\build\src\e7t\devices\led_driver.c
 - SLOS\build\src\e7t\devices\segment_driver.c
 - SLOS\build\src\e7t\devices\serial_driver.c
 - SLOS\build\src\e7t\devices\serial_driver.h
 - SLOS\build\src\e7t\events\tick_service.c
 - SLOS\build\src\e7t\events\tick_service.h
 - each directory's tags file