code_size_compare.py: change default path of armclang

Signed-off-by: Yanray Wang <yanray.wang@arm.com>
diff --git a/scripts/code_size_compare.py b/scripts/code_size_compare.py
index afc2c59..86facb9 100755
--- a/scripts/code_size_compare.py
+++ b/scripts/code_size_compare.py
@@ -88,7 +88,7 @@
         elif self.arch == SupportedArch.AARCH32.value and \
              self.config == SupportedConfig.TFM_MEDIUM.value:
             return \
-                 'make -j lib CC=/usr/local/ArmCompilerforEmbedded6.19/bin/armclang \
+                 'make -j lib CC=armclang \
                   CFLAGS=\'--target=arm-arm-none-eabi -mcpu=cortex-m33 -Os \
                  -DMBEDTLS_CONFIG_FILE=\\\"' + CONFIG_TFM_MEDIUM_MBEDCRYPTO_H + '\\\" \
                  -DMBEDTLS_PSA_CRYPTO_CONFIG_FILE=\\\"' + CONFIG_TFM_MEDIUM_PSA_CRYPTO_H + '\\\" \''