Sysv format for ChibiOS arm-none-eabi-size

Some new patches to ChibiOS puts heap as it's own section. So the
berkeley format is now useless, as the heap will be included in the
BSS report. The sysv format displays the bss size correctly.

Author: fredizzimo

tool/chibios/chibios.mk

@@ -175,7 +175,7 @@ CP   = $(TRGT)objcopy
 AS   = $(TRGT)gcc -x assembler-with-cpp
 AR   = $(TRGT)ar
 OD   = $(TRGT)objdump
-SZ   = $(TRGT)size
+SZ   = $(TRGT)size -A
 HEX  = $(CP) -O ihex
 BIN  = $(CP) -O binary