Revert "build_helper: Add toolchain file arg in nspe build command"

This reverts commit e696901fc8e6f67a5ca738bfeb2fb04c2358998c.

Reason for revert: nspe build command expects different toolchain file name. The `compiler` value set for spe build cannot be directly reused in nspe build

Change-Id: Id96eb3b1e2f58ee04077dd185879e1ca9b80f1b2
Signed-off-by: David Hu <david.hu@arm.com>
diff --git a/build_helper/build_helper_configs.py b/build_helper/build_helper_configs.py
index 319a7d4..ebe61ae 100755
--- a/build_helper/build_helper_configs.py
+++ b/build_helper/build_helper_configs.py
@@ -67,7 +67,6 @@
     "nspe_config_template": "cmake -G Ninja " + \
         "-S %(tfm_tests_root_dir)s/%(test_root_dir)s " + \
         "-B %(ci_build_root_dir)s/nspe " + \
-        "-DTFM_TOOLCHAIN_FILE=%(ci_build_root_dir)s/spe/api_ns/cmake/%(compiler)s " + \
         "-DCONFIG_SPE_PATH=%(ci_build_root_dir)s/spe/api_ns " + \
         "%(extra_params)s " + \
         "-DQCBOR_PATH=%(codebase_root_dir)s/../qcbor ",