package/clang: fix host-clang binaries

This patch fixes the following error when trying to execute clang compiler
(host-variant):

CommandLine Error: Option 'x86-use-base-pointer' registered more than once!
LLVM ERROR: inconsistency in registered CommandLine options

The same happens for the other binaries, such as clang-format:

./clang-format
: CommandLine Error: Option 'help-list' registered more than once!
LLVM ERROR: inconsistency in registered CommandLine options

Clang binaries are tools, and given that DLLVM_LINK_LLVM_DYLIB is set,
they are linked against libLLVM.so. The problem is that binaries are
also linking against some LLVM static libraries, resulting in the error
shown above. However, it is not the same case for libclang, which is also
a tool but links only against libLLVM.so.

To fix this problem, add LLVM_DYLIB_COMPONENTS=all.

Signed-off-by: Valentin Korenblit <valentin.korenblit@smile.fr>
Tested-by: Joseph Kogut <joseph.kogut@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>