-mcpu option not needed for v8M devices

-mcpu option if set for v8M CPU;s it will add DSP feature as default
which is optional. Hence setting just the architecture for Cortex-M23
and Cortex-M33

Author: deepikabhavnani

tools/toolchains/arm.py

@@ -393,11 +393,7 @@ def __init__(self, target, *args, **kwargs):
             self.flags['common'].append("-mcpu=%s" % target.core.lower()[:-1])
             self.flags['ld'].append("--cpu=%s" % target.core.lower()[:-1])
             self.SHEBANG += " -mcpu=%s" % target.core.lower()[:-1]
-        elif target.core.lower().endswith("ns"):
-            self.flags['common'].append("-mcpu=%s" % target.core.lower()[:-3])
-            self.flags['ld'].append("--cpu=%s" % target.core.lower()[:-3])
-            self.SHEBANG += " -mcpu=%s" % target.core.lower()[:-3]
-        else:
+        elif not target.core.startswith("Cortex-M23") and not target.core.startswith("Cortex-M33"):
             self.flags['common'].append("-mcpu=%s" % target.core.lower())
             self.flags['ld'].append("--cpu=%s" % target.core.lower())
             self.SHEBANG += " -mcpu=%s" % target.core.lower()