Sync RAM sizes for Arduino-enabled L4-based boards // Resolve #537

STM32L4 targets may have several separate blocks of SRAM,
for example STM32L476RGT6 has two blocks (96KB + 32KB)
To properly configure Arduino framework we need pass the size of
the first bank SRAM1 via the LD_MAX_DATA_SIZE define.

Author: valeros

boards/disco_l475vg_iot01a.json

@@ -40,7 +40,7 @@
   ],
   "name": "ST B-L475E-IOT01A Discovery kit",
   "upload": {
-    "maximum_ram_size": 131072,
+    "maximum_ram_size": 98304,
     "maximum_size": 1048576,
     "protocol": "stlink",
     "protocols": [

boards/nucleo_l452re.json

@@ -31,8 +31,8 @@
   ],
   "name": "ST Nucleo L452RE",
   "upload": {
-    "maximum_ram_size": 65536,
-    "maximum_size": 262144,
+    "maximum_ram_size": 163840,
+    "maximum_size": 524288,
     "protocol": "stlink",
     "protocols": [
       "jlink",

boards/nucleo_l476rg.json

@@ -33,7 +33,7 @@
   ],
   "name": "ST Nucleo L476RG",
   "upload": {
-    "maximum_ram_size": 131072,
+    "maximum_ram_size": 98304,
     "maximum_size": 1048576,
     "protocol": "stlink",
     "protocols": [

boards/nucleo_l496zg.json

@@ -33,7 +33,7 @@
   ],
   "name": "ST Nucleo L496ZG",
   "upload": {
-    "maximum_ram_size": 131072,
+    "maximum_ram_size": 327680,
     "maximum_size": 1048576,
     "protocol": "stlink",
     "protocols": [