[SYCL][Driver][Test] Remove unnecessary 'sysroot' usage in driver lit tests

[jinge90]

We added '--sysroot=%S/Inputs/SYCL' to SYCL driver lit tests to locate dummy devicelibs to remove dependency on building libdevice. Some of the additions are not needed in fact, this PR cleans up these redundant sysroot usage.
The updated tests can be categorized into:

1. use -ccc-print-phases in command to dump action graph only, no devicelib lookup happen:
   sycl-int-header-footer, sycl-preprocess and phase lines in sycl-offload*
2. Driver error before jobs are built. These are not lines that check option validation: invalid or unknown target, bad option value, bad --offload-arch, incompatible option, empty -fsycl-host-compiler=, and so on. The driver stops right after the diagnostic.
   sycl-offload.cpp 10–110, 551, 553. sycl-ftarget-register-alloc-mode; sycl-host-compiler; sycl-lto; sycl-fsyclbin
3. Object or archive input only, no source file. The driver doesn't compile anything for the device. The device link is passed to clang-linker-wrapper, and the checks only look at its options.
   sycl-option-ownership, sycl-offload.cpp 661–690. sycl-offload-new-driver.cpp:171, sycl-spirv-obj.cpp:39
4. SYCLBIN inputs or -fsycl-link of .syclbin. There's no device compile, and the checks are on the syclbin link commands.
   sycl-syclbin-link
5. --no-offloadlib already given. Device libraries are turned off.
   sycl-offload-save-temps, sycl-offload-with-split, sycl-save-offload-code
6. Stops before the device compile. -E, -fsycl-device-only/--offload-device-only with phases, or -fsycl-help.
   sycl-syclbin-link, sycl-offload
7. Empty -fsycl-targets=. No device toolchain is created; only a warning is checked.
   sycl-offoad.cpp

Build clang and related tools required by running clang driver tests and run all driver tests, all updated tests passed without build libdevice binaries.

[jinge90]

Hi, @mdtoguchi
Could you help review this PR?
Thanks very much.