Update the winsdk-tools prerequisites.

To build the windows SDK tools, we need only the Linux llvm-tblgen and
clang-tblgen, but not llvm-rs-cc or bcc_compat.
This reduces significantly build time if you want run only "make
winsdk-tools".

Bug: 19149444
Change-Id: I971dd6a6e1a7dd11a968ee8be8cd02085055c262
1 file changed