CPU: Get rid of the unused ev5_trap function on the simple and checker CPUs.

src/cpu/checker/cpu.hh

@@ -293,7 +293,6 @@ class CheckerCPU : public BaseCPU
 
 #if FULL_SYSTEM
     Fault hwrei() { return thread->hwrei(); }
-    void ev5_trap(Fault fault) { fault->invoke(tc); }
     bool simPalCheck(int palFunc) { return thread->simPalCheck(palFunc); }
 #else
     // Assume that the normal CPU's call to syscall was successful.

src/cpu/simple/base.hh

@@ -387,7 +387,6 @@ class BaseSimpleCPU : public BaseCPU
 
 #if FULL_SYSTEM
     Fault hwrei() { return thread->hwrei(); }
-    void ev5_trap(Fault fault) { fault->invoke(tc); }
     bool simPalCheck(int palFunc) { return thread->simPalCheck(palFunc); }
 #else
     void syscall(int64_t callnum) { thread->syscall(callnum); }