gallivm: Fix build - Remove TargetOptions.RealignStack for llvm>=3.4

Since llvm -3.4svn r187618, TargetOptions doesn't provide
RealignStack, so only enable it with llvm<3.4

This option must now be specified using function attributes, see LLVM
commit r187618

Reviewed-by: Tom Stellard <thomas.stellard@amd.com>

src/gallium/auxiliary/gallivm/lp_bld_misc.cpp

@@ -273,8 +273,10 @@ lp_build_create_jit_compiler_for_module(LLVMExecutionEngineRef *OutJIT,
    TargetOptions options;
 #if defined(PIPE_ARCH_X86)
    options.StackAlignmentOverride = 4;
+#if HAVE_LLVM < 0x0304
    options.RealignStack = true;
 #endif
+#endif
 
 #if defined(DEBUG)
    options.JITEmitDebugInfo = true;