[SYCL][NATIVECPU] Fix SYCL header inclusion on Native CPU tests (#15551)

Fix `sycl.hpp` inclusion on Native CPU `check_device_code` tests.

Author: PietroGhg

sycl/test/check_device_code/native_cpu/local_module_scope.cpp

@@ -11,7 +11,7 @@
 // CHECK: alloca %localVarTypes
 // CHECK: attributes #[[ATTR]] = {{.*}} "mux-orig-fn"="_ZTS4TestILi1ELi4EiE"
 
-#include "sycl.hpp"
+#include <sycl/sycl.hpp>
 
 template <int dims, int size, typename T = int> struct Test;
 

sycl/test/check_device_code/native_cpu/native_cpu_attrs.cpp

@@ -3,7 +3,7 @@
 // RUN: FileCheck %s --input-file %t.ll --check-prefix=CHECK-WG-BARRIER
 // RUN: FileCheck %s --input-file %t.ll
 
-#include "sycl.hpp"
+#include <sycl/sycl.hpp>
 using namespace sycl;
 
 class Test;

sycl/test/check_device_code/native_cpu/native_cpu_builtins.cpp

@@ -14,7 +14,7 @@
 
 // CHECK-NOT: define internal{{.*}}__mux_sub_group_shuffle
 
-#include "sycl.hpp"
+#include <sycl/sycl.hpp>
 class Test1;
 class Test2;
 class Test3;