upgrade xdnn (#133)

Author: pujiang2018

cmake/xdnn.cmake

@@ -26,8 +26,8 @@ include(ExternalProject)
 
 # cmake-format: off
 ExternalProject_Add(xdnn_lib
-  URL               https://github.com/intel/xFasterTransformer/releases/download/IntrinsicGemm/xdnn_v1.5.5.tar.gz
-  URL_HASH          MD5=190dc05eb28c239fb70002348d8e18dd
+  URL               https://github.com/intel/xFasterTransformer/releases/download/IntrinsicGemm/xdnn_v1.5.6.tar.gz
+  URL_HASH          MD5=86a90f1a232baaa17bd19b5acab3b194
   TIMEOUT           120
   SOURCE_DIR        ${CMAKE_SOURCE_DIR}/3rdparty/xdnn
   CONFIGURE_COMMAND ""