examples: add opencm9-04 to unsufficient memory boards in some examples

examples/dtls-echo/Makefile

@@ -17,7 +17,7 @@ BOARD_INSUFFICIENT_MEMORY := airfy-beacon nrf51dongle nrf6310 nucleo-f103 \
                              nucleo-f334 pca10000 pca10005 spark-core \
                              stm32f0discovery weio yunjia-nrf51822 nucleo-f072 \
                              cc2650stk nucleo-f030 nucleo-f070 microbit \
-                             calliope-mini nucleo32-f042 nucleo32-f303
+                             calliope-mini nucleo32-f042 nucleo32-f303 opencm9-04
 
 # Include packages that pull up and auto-init the link layer.
 # NOTE: 6LoWPAN will be included if IEEE802.15.4 devices are present

examples/gnrc_border_router/Makefile

@@ -12,7 +12,7 @@ BOARD_INSUFFICIENT_MEMORY := airfy-beacon cc2650stk msb-430 msb-430h pca10000 pc
                              spark-core stm32f0discovery telosb \
                              weio wsn430-v1_3b wsn430-v1_4 yunjia-nrf51822 z1 nucleo-f072 \
                              nucleo-f030 nucleo-f070 microbit calliope-mini \
-                             nucleo32-f042 nucleo32-f303
+                             nucleo32-f042 nucleo32-f303 opencm9-04
 
 # use ethos (ethernet over serial) for network communication and stdio over
 # UART, but not on native, as native has a tap interface towards the host.