fix typo board defines for feather m0 express (#325)

Author: hathach

boards.txt

@@ -106,7 +106,7 @@ adafruit_feather_m0_express.build.usb_product="Feather M0 Express"
 adafruit_feather_m0_express.build.usb_manufacturer="Adafruit"
 adafruit_feather_m0_express.build.board=SAMD_FEATHER_M0_EXPRESS
 adafruit_feather_m0_express.build.core=arduino
-adafruit_feather_m0_express.build.extra_flags=-D__SAMD21G18A__ -DARDUINO_SAMD_FEATHER_M0 -DARDUINO_SAMD_FEATHER_M0 -DARDUINO_SAMD_ZERO -DARM_MATH_CM0PLUS {build.usb_flags}
+adafruit_feather_m0_express.build.extra_flags=-D__SAMD21G18A__ -DARDUINO_SAMD_FEATHER_M0 -DADAFRUIT_FEATHER_M0_EXPRESS -DARDUINO_SAMD_ZERO -DARM_MATH_CM0PLUS {build.usb_flags}
 adafruit_feather_m0_express.build.ldscript=linker_scripts/gcc/flash_with_bootloader.ld
 adafruit_feather_m0_express.build.openocdscript=openocd_scripts/feather_m0_express.cfg
 adafruit_feather_m0_express.build.variant=feather_m0_express

extras/makeboards.py

@@ -169,7 +169,7 @@ def make_board(mcu, name, variant, vendor, product, vid, pid_list, boarddefine,
 
 make_board("SAMD21", "adafruit_feather_m0_express", "feather_m0_express", 
            "Adafruit", "Feather M0 Express", "0x239A", ["0x801B", "0x001B"],
-           "SAMD_FEATHER_M0_EXPRESS", "-D__SAMD21G18A__ -DARDUINO_SAMD_FEATHER_M0 -DARDUINO_SAMD_FEATHER_M0", "featherM0/bootloader-feather_m0-v2.0.0-adafruit.5.bin")
+           "SAMD_FEATHER_M0_EXPRESS", "-D__SAMD21G18A__ -DARDUINO_SAMD_FEATHER_M0 -DADAFRUIT_FEATHER_M0_EXPRESS", "featherM0/bootloader-feather_m0-v2.0.0-adafruit.5.bin")
 
 make_board("SAMD21", "adafruit_metro_m0", "metro_m0", 
            "Adafruit", "Metro M0 Express", "0x239A", ["0x8013", "0x0013"],