fix FlashDecoding change's regression in intel platform (#2161)

install triton because GPTQParams needs it.
Signed-off-by: Wang, Yi A <yi.a.wang@intel.com>

Dockerfile_intel

@@ -62,6 +62,7 @@ ENV HUGGINGFACE_HUB_CACHE=/data \
 
 WORKDIR /usr/src
 RUN wget https://intel-extension-for-pytorch.s3.amazonaws.com/ipex_dev/xpu/torch-2.1.0.post1%2Bcxx11.abi-cp310-cp310-linux_x86_64.whl && pip install torch-2.1.0.post1+cxx11.abi-cp310-cp310-linux_x86_64.whl
+RUN pip install https://github.com/intel/intel-xpu-backend-for-triton/releases/download/v2.1.0/triton-2.1.0-cp310-cp310-manylinux_2_17_x86_64.manylinux2014_x86_64.whl
 RUN git clone https://github.com/intel/intel-extension-for-pytorch && cd intel-extension-for-pytorch && git checkout -b distributed origin/dev/distributed
 
 # Install server
@@ -132,6 +133,7 @@ RUN conda install -c conda-forge gperftools mkl
 RUN pip install https://download.pytorch.org/whl/nightly/cpu/torch-2.4.0.dev20240612%2Bcpu-cp310-cp310-linux_x86_64.whl
 RUN pip install https://download.pytorch.org/whl/nightly/cpu/torchvision-0.19.0.dev20240612%2Bcpu-cp310-cp310-linux_x86_64.whl
 RUN pip install https://download.pytorch.org/whl/nightly/cpu/torchaudio-2.4.0.dev20240612%2Bcpu-cp310-cp310-linux_x86_64.whl
+RUN pip install triton
 
 WORKDIR /usr/src
 

server/text_generation_server/layers/attention/ipex.py

 import intel_extension_for_pytorch as ipex
 import torch
 from text_generation_server.models.flash_causal_lm import BLOCK_SIZE
+from text_generation_server.layers.attention import Seqlen
 
 SUPPORTS_WINDOWING = False
 
@@ -55,11 +56,10 @@ def paged_attention(
     kv_head_mapping: torch.Tensor,
     softmax_scale: float,
     block_tables: torch.Tensor,
-    cu_seqlen_q: torch.Tensor,
-    cu_seqlen_k: torch.Tensor,
+    seqlen: Seqlen,
     max_s: int,
 ):
-    return ipex.llm.modules.PagedAttention.single_query_cached_kv_attention(
+    ipex.llm.modules.PagedAttention.single_query_cached_kv_attention(
         out,
         query,
         key_cache,
@@ -67,8 +67,9 @@ def paged_attention(
         kv_head_mapping,
         softmax_scale,
         block_tables,
-        cu_seqlen_q,
+        seqlen.input_lengths,
         BLOCK_SIZE,
         max_s,
         None,
     )
+    return out