Merge pull request #2287 from Xreki/fix_typo_openblas

Fix typo of setting openblas compiling flags.

cmake/external/openblas.cmake

@@ -37,7 +37,7 @@ IF(NOT ${CBLAS_FOUND})
         SET(OPTIONAL_ARGS HOSTCC=${HOST_C_COMPILER} TARGET=ARMV7 USE_THREAD=0 libs)
     ELSE()
         SET(OPENBLAS_COMMIT "v0.2.19")
-        SET(OPENBLAS_ARGS DYNAMIC_ARCH=1 libs)
+        SET(OPTIONAL_ARGS DYNAMIC_ARCH=1 libs)
     ENDIF()
 
     ExternalProject_Add(