[SYCL] Remove tests migrated to llvm-test-suite (#2611)

The tests have been submitted in scope of intel/llvm-test-suite#29

Author: vladimirlaz

sycl/test/esimd/on-device/BitonicSortK.cpp

@@ -1,4 +1,6 @@
-This directory contains ESIMD tests which are run on Intel GPU device only.
-Some of them can run on host device too, but in general it is not always
-possible as some of ESIMD APIs (e.g. memory access via accessors) is not
-implemented for the host device.
+The tests from these directory are moved to LLVM test suite reporitory:
+[SYCL/ESIMD](https://github.com/intel/llvm-test-suite/tree/intel/SYCL/ESIMD).
+
+Contribution process is described in [CONTRIBUTING.md](https://github.com/intel/llvm-test-suite/blob/intel/CONTRIBUTING.md)
+
+These tests are run as part of post-commit testing.