Added Apple Silicon GPU device update (#820)

* Added Apple Silicon GPU device

* Added Apple Silicon GPU device

* delete: remove unused model.pth file from understanding-buffers

* update

* update

---------

Co-authored-by: missflash <missflash@gmail.com>

ch03/02_bonus_efficient-multihead-attention/mha-implementations.ipynb

@@ -58,6 +58,7 @@
      "name": "stdout",
      "output_type": "stream",
      "text": [
+      "Using device: cuda\n",
       "PyTorch version: 2.8.0\n"
      ]
     }
@@ -66,7 +67,14 @@
     "import torch\n",
     "\n",
     "torch.manual_seed(123)\n",
-    "device = torch.device(\"cuda\" if torch.cuda.is_available() else \"cpu\")\n",
+    "if torch.backends.mps.is_available():\n",
+    "    device = torch.device(\"mps\")   # Apple Silicon GPU (Metal)\n",
+    "elif torch.cuda.is_available():\n",
+    "    device = torch.device(\"cuda\")  # NVIDIA GPU\n",
+    "else:\n",
+    "    device = torch.device(\"cpu\")   # CPU fallback\n",
+    "\n",
+    "print(f\"Using device: {device}\")\n",
     "print(f\"PyTorch version: {torch.__version__}\")\n",
     "\n",
     "batch_size = 8\n",