Build: Fix configurations of build log quietly

Change-Id: Ieb765d457250da66f5c5144b0bf1cbbad4dc32b7
Signed-off-by: Kevin Peng <kevin.peng@arm.com>
diff --git a/toolchain_GNUARM.cmake b/toolchain_GNUARM.cmake
index f1104e3..8b66c5b 100644
--- a/toolchain_GNUARM.cmake
+++ b/toolchain_GNUARM.cmake
@@ -52,7 +52,7 @@
     )
 endmacro()
 
-if(TFM_MEMORY_USAGE_QUIET)
+if(CONFIG_TFM_MEMORY_USAGE_QUIET)
     set(MEMORY_USAGE_FLAG "")
 else()
     set(MEMORY_USAGE_FLAG LINKER:--print-memory-usage)