sim: Remove redundant export_method_cxx_predecls

The headers declared in export_method_cxx_predecls are redundant since a
SimObject's main header is automatically included.

Change-Id: Ied9e84630b36960e54efe91d16f8c66fba7e0da0
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-by: Joe Gross <joseph.gross@amd.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>

src/arch/arm/ArmSystem.py

@@ -98,10 +98,6 @@ class LinuxArmSystem(GenericArmSystem):
     type = 'LinuxArmSystem'
     cxx_header = "arch/arm/linux/system.hh"
 
-    @classmethod
-    def export_method_cxx_predecls(cls, code):
-        code('#include "arch/arm/linux/system.hh"')
-
     @classmethod
     def export_methods(cls, code):
         code('''void dumpDmesg();''')