Update config, bootloader and readme

Author: toyowata

README.md

@@ -28,6 +28,7 @@ Board                          |  Connectivity     | Storage for credentials and
 `ST NUCLEO_L4R5ZI`                  | Wi-Fi ESP8266     | Internal Flash          | Build-only
 `Nuvoton NUMAKER_IOT_M487`          | Wi-Fi ESP8266     | SD card (NUSD)          | Build-only
 `Seeed ARCH_MAX`                    | Ethernet          | SD card                 | Build-only
+`Seeed Wio 3G`                      | Cellular          | Internal Flash          | Build-only
 `Renesas RZ_A1H`                    | Ethernet          | External Flash ([See security limitation of this board](https://os.mbed.com/platforms/Renesas-GR-PEACH/#security-limitation-of-this-platform)) | Build-only
 `Renesas GR_LYCHEE`                 | Wi-Fi (ESP32)     | External Flash ([See security limitation of this board](https://os.mbed.com/platforms/Renesas-GR-LYCHEE/#security-limitation-of-this-platform)) | Build-only
 

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

@@ -390,6 +390,7 @@
             "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,
@@ -406,7 +407,7 @@
             "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"
         }
     },