ARMC6: Use float-abi=hard

For binary compatibility with ARMC5, use the hard ABI variant whenever
we have FP hardware - this is ARMC5's default behaviour, which we do not
override.

Cortex-M4F was already using hard; this brings M7F and M33F into line.

Author: kjbracey

tools/toolchains/arm.py

@@ -415,15 +415,15 @@ def __init__(self, target, *args, **kwargs):
             self.flags['common'].append("-mfloat-abi=hard")
         elif target.core == "Cortex-M7F":
             self.flags['common'].append("-mfpu=fpv5-sp-d16")
-            self.flags['common'].append("-mfloat-abi=softfp")
+            self.flags['common'].append("-mfloat-abi=hard")
         elif target.core == "Cortex-M7FD":
             self.flags['common'].append("-mfpu=fpv5-d16")
-            self.flags['common'].append("-mfloat-abi=softfp")
+            self.flags['common'].append("-mfloat-abi=hard")
         elif target.core.startswith("Cortex-M23"):
             self.flags['common'].append("-march=armv8-m.base")
         elif target.core.startswith("Cortex-M33F"):
             self.flags['common'].append("-mfpu=fpv5-sp-d16")
-            self.flags['common'].append("-mfloat-abi=softfp")
+            self.flags['common'].append("-mfloat-abi=hard")
 
         if ((target.core.startswith("Cortex-M23") or
              target.core.startswith("Cortex-M33")) and