cpu: Remove unused getBranchPred() method from BaseCPU

Remove unused virtual getBranchPred() method from BaseCPU as it is not
implemented by any of the CPU models. It used to always return NULL.

src/cpu/base.hh

@@ -60,7 +60,6 @@
 #include "sim/system.hh"
 
 struct BaseCPUParams;
-class BranchPred;
 class CheckerCPU;
 class ThreadContext;
 
@@ -393,12 +392,6 @@ class BaseCPU : public MemObject
     virtual void unserializeThread(Checkpoint *cp, const std::string &section,
                                    ThreadID tid) {};
 
-    /**
-     * Return pointer to CPU's branch predictor (NULL if none).
-     * @return Branch predictor pointer.
-     */
-    virtual BranchPred *getBranchPred() { return NULL; };
-
     virtual Counter totalInsts() const = 0;
 
     virtual Counter totalOps() const = 0;