Move the docsdir to /usr/share/doc/llvm to match other projects.

Fixes PR6267.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97549 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/configure b/configure
index b3f1603..2b597a1 100755
--- a/configure
+++ b/configure
@@ -19732,7 +19732,7 @@
 eval LLVM_BINDIR="${prefix}/bin";
 eval LLVM_LIBDIR="${prefix}/lib";
 eval LLVM_DATADIR="${prefix}/share/llvm";
-eval LLVM_DOCSDIR="${prefix}/docs/llvm";
+eval LLVM_DOCSDIR="${prefix}/share/doc/llvm";
 eval LLVM_ETCDIR="${prefix}/etc/llvm";
 eval LLVM_INCLUDEDIR="${prefix}/include";
 eval LLVM_INFODIR="${prefix}/info";