make LED definitions board specific

the LEDs (2 of them) were connected to the same pins on all
boards, up to the octsim-tester.
to be able to have board specific LEDs the definitions have moved
from common to the each board.
at the same time I added a bit of documentation what the LEDs are
used for.

Change-Id: I3226a9187a8d0b657ccf5dcd8f3586b2578f96d2
diff --git a/firmware/libboard/simtrace/include/board.h b/firmware/libboard/simtrace/include/board.h
index 7703451..c109bea 100644
--- a/firmware/libboard/simtrace/include/board.h
+++ b/firmware/libboard/simtrace/include/board.h
@@ -31,6 +31,21 @@
 /** desired main clock frequency (in Hz, based on BOARD_MAINOSC) */
 #define BOARD_MCK 58982400 // 18.432 * 16 / 5
 
+/** MCU pin connected to red LED */
+#define PIO_LED_RED     PIO_PA17
+/** MCU pin connected to green LED */
+#define PIO_LED_GREEN   PIO_PA18
+/** red LED pin definition */
+#define PIN_LED_RED     {PIO_LED_RED, PIOA, ID_PIOA, PIO_OUTPUT_1, PIO_DEFAULT}
+/** green LED pin definition */
+#define PIN_LED_GREEN   {PIO_LED_GREEN, PIOA, ID_PIOA, PIO_OUTPUT_1, PIO_DEFAULT}
+/** LEDs pin definition */
+#define PINS_LEDS       PIN_LED_RED, PIN_LED_GREEN 
+/** index for red LED in LEDs pin definition array */
+#define LED_NUM_RED     0
+/** index for green LED in LEDs pin definition array */
+#define LED_NUM_GREEN   1
+
 /** Pin configuration **/
 /* Button to force bootloader start (shorted to ground when pressed */
 #define PIN_BOOTLOADER_SW      {PIO_PA31, PIOA, ID_PIOA, PIO_INPUT, PIO_PULLUP}