cmake: cache line size detection

Change-Id: I9a0df8d15deefdf31cfead56c96433cd7220b802
Signed-off-by: Damjan Marion <damarion@cisco.com>
diff --git a/src/vppinfra/CMakeLists.txt b/src/vppinfra/CMakeLists.txt
index 1b2797a..d5242e8 100644
--- a/src/vppinfra/CMakeLists.txt
+++ b/src/vppinfra/CMakeLists.txt
@@ -16,7 +16,7 @@
 ##############################################################################
 # Generate vppinfra/config.h
 ##############################################################################
-set(LOG2_CACHE_LINE_BYTES 6)
+set(LOG2_CACHE_LINE_BYTES ${VPP_LOG2_CACHE_LINE_SIZE})
 option(VPP_USE_DLMALLOC "Use dlmalloc memory allocator." ON)
 if(VPP_USE_DLMALLOC)
   set(DLMALLOC 1)