Expose NASM variable in ccmake


git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/branches/1.1.x@726 632fc199-4ca6-4c93-a231-07263d6284db
diff --git a/simd/CMakeLists.txt b/simd/CMakeLists.txt
index 263579d..d956dac 100755
--- a/simd/CMakeLists.txt
+++ b/simd/CMakeLists.txt
@@ -1,5 +1,5 @@
 if(NOT DEFINED NASM)
-  set(NASM nasm)
+  set(NASM nasm CACHE PATH "Path to NASM/YASM executable")
 endif()
 
 if(SIMD_X86_64)