configure.ac: Move HAVE_LLVM definition into configure.ac

Otherwise HAVE_LLVM won't be included in the $(DEFINES) variable for
Automake generated Makefiles.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

configs/autoconf.in

@@ -217,9 +217,5 @@ WAYLAND_LIBS = @WAYLAND_LIBS@
 MESA_LLVM = @MESA_LLVM@
 
 LLVM_VERSION = @LLVM_VERSION@
-ifneq ($(LLVM_VERSION),)
-  HAVE_LLVM := 0x0$(subst .,0,$(LLVM_VERSION:svn=))
-  DEFINES += -DHAVE_LLVM=$(HAVE_LLVM)
-endif
 
 HAVE_XF86VIDMODE = @HAVE_XF86VIDMODE@

configure.ac

@@ -1805,7 +1805,7 @@ if test "x$enable_gallium_llvm" = xyes; then
 	LLVM_BINDIR=`$LLVM_CONFIG --bindir`
 	LLVM_CXXFLAGS=`$LLVM_CONFIG --cxxflags`
 	LLVM_INCLUDEDIR=`$LLVM_CONFIG --includedir`
-	DEFINES="$DEFINES -D__STDC_CONSTANT_MACROS"
+	DEFINES="${DEFINES} -DHAVE_LLVM=`echo $LLVM_VERSION | sed -e 's/\([[0-9]]\)\.\([[0-9]]\)/0x0\10\2/g'`"
 	MESA_LLVM=1
     else
 	MESA_LLVM=0