add heltec meshpocket board.

boards/heltec_mesh_pocket.json

@@ -0,0 +1,53 @@
+{
+    "build": {
+      "arduino": {
+        "ldscript": "nrf52840_s140_v6.ld"
+      },
+      "core": "nRF5",
+      "cpu": "cortex-m4",
+      "extra_flags": "-DNRF52840_XXAA",
+      "f_cpu": "64000000L",
+      "hwids": [
+        ["0x239A", "0x4405"],
+        ["0x239A", "0x0029"],
+        ["0x239A", "0x002A"]
+      ],
+      "usb_product": "HT-n5262",
+      "mcu": "nrf52840",
+      "variant": "heltec_mesh_pocket",
+      "variants_dir": "variants",
+      "bsp": {
+        "name": "adafruit"
+      },
+      "softdevice": {
+        "sd_flags": "-DS140",
+        "sd_name": "s140",
+        "sd_version": "6.1.1",
+        "sd_fwid": "0x00B6"
+      },
+      "bootloader": {
+        "settings_addr": "0xFF000"
+      }
+    },
+    "connectivity": ["bluetooth"],
+    "debug": {
+      "jlink_device": "nRF52840_xxAA",
+      "onboard_tools": ["jlink"],
+      "svd_path": "nrf52840.svd",
+      "openocd_target": "nrf52840-mdk-rs"
+    },
+    "frameworks": ["arduino"],
+    "name": "Heltec nrf (Adafruit BSP)",
+    "upload": {
+      "maximum_ram_size": 248832,
+      "maximum_size": 815104,
+      "speed": 115200,
+      "protocol": "nrfutil",
+      "protocols": ["jlink", "nrfjprog", "nrfutil", "stlink"],
+      "use_1200bps_touch": true,
+      "require_upload_port": true,
+      "wait_for_upload_port": true
+    },
+    "url": "https://heltec.org/project/meshpocket/",
+    "vendor": "Heltec"
+  }