Update config, bootloader and readme

Author: toyowata

README.md

@@ -27,6 +27,7 @@ Board                          |  Connectivity     | Storage for credentials and
 `ST NUCLEO_H743ZI2`                 | Ethernet          | Internal Flash          | Build-only
 `ST NUCLEO_L4R5ZI`                  | Wi-Fi ESP8266     | Internal Flash          | Build-only
 `Nuvoton NUMAKER_IOT_M487`          | Wi-Fi ESP8266     | SD card (NUSD)          | Build-only
+`Seeed Wio 3G`                      | Cellular          | Internal Flash          | Build-only
 
 Build-only = This target is currently verified only via compilation, and is not verified at runtime.
 

bootloader/mbed-bootloader-wio_3g-internal_flash-no_rot-v4.1.2.bin

@@ -327,6 +327,7 @@
             "target.bootloader_img"                     : "bootloader/mbed-bootloader-wio_3g-internal_flash-no_rot-v4.1.2.bin",
             "target.header_offset"                      : "0x8000",
             "target.app_offset"                         : "0x8400",
+            "target.restrict_size"                      : "0xF4000",
             "nsapi.default-cellular-plmn"               : 0,
             "cellular.use-apn-lookup"                   : false,
             "cellular.debug-at"                         : false,
@@ -343,7 +344,7 @@
             "update-client.storage-page"                : 1,
             "mbed-cloud-client.update-storage"          : "ARM_UCP_FLASHIAP",
             "storage_tdb_internal.internal_base_address": "(MBED_ROM_START+1024*1024)",
-            "storage_tdb_internal.internal_size"        : "(128*1024)",
+            "storage_tdb_internal.internal_size"        : "(32*1024)",
             "storage.storage_type"                      : "TDB_INTERNAL"
         }
     },