Fix STM32F407VG Ram Size (#452)

Author: rhapsodyv

boards/genericSTM32F407VGT6.json

@@ -36,10 +36,10 @@
     "stm32cube",
     "libopencm3"
   ],
-  "name": "STM32F407VG (192k RAM. 1024k Flash)",
+  "name": "STM32F407VG (128k RAM. 1024k Flash)",
   "upload": {
     "disable_flushing": false,
-    "maximum_ram_size": 196608,
+    "maximum_ram_size": 131072,
     "maximum_size": 1048576,
     "protocol": "stlink",
     "protocols": [