Performance: Add support for split build

Rename the SPE and NSPE source root directories.

Signed-off-by: Jianliang Shen <jianliang.shen@arm.com>
Change-Id: I5891a47ab00078e7f0c6429d28925786094bd149
diff --git a/performance.py b/performance.py
index 3fa96b4..97c6554 100755
--- a/performance.py
+++ b/performance.py
@@ -44,7 +44,7 @@
     '''
     This function uses fromelf of ARMCLANG to get the sizes of a file in the build binary directory of TF-M
     '''
-    f_path = os.path.join(os.getenv('WORKSPACE'), 'trusted-firmware-m', 'build', 'bin', filename)
+    f_path = os.path.join(os.getenv('WORKSPACE'), 'ci_build', 'spe', 'bin', filename)
     if os.path.exists(f_path) :
         data_fromelf = utils.fromelf(f_path)
         print(data_fromelf[1])  # Output of fromelf