examples: removed superfluous blacklisting

ATmega now has a panic function, no need for blacklisting any more.

examples/gnrc_border_router/Makefile

@@ -10,8 +10,6 @@ RIOTBASE ?= $(CURDIR)/../..
 BOARD_INSUFFICIENT_MEMORY := airfy-beacon nrf51dongle nrf6310 pca10000 pca10005 nucleo-f334 \
                              spark-core stm32f0discovery yunjia-nrf51822
 
-BOARD_BLACKLIST := arduino-mega2560     # panic_arch not defined
-
 ifeq (,$(SLIP_UART))
   # set default (last available UART)
   SLIP_UART="(UART_NUMOF-1)"

examples/gnrc_networking/Makefile

@@ -12,7 +12,7 @@ BOARD_INSUFFICIENT_MEMORY := airfy-beacon chronos msb-430 msb-430h nrf51dongle \
                           stm32f0discovery telosb wsn430-v1_3b wsn430-v1_4 \
                           yunjia-nrf51822 z1
 
-BOARD_BLACKLIST        := arduino-mega2560 spark-core
+BOARD_BLACKLIST        := spark-core
 # arduino-mega2560: unknown error types (e.g. -EBADMSG)
 
 # Include packages that pull up and auto-init the link layer.