cpu, power: Get rid of the remnants of the EA computation insts.

Get rid of some remnants of a system which was intended to separate
address computation into its own instruction object.

Change-Id: I23f9ffd70fcb89a8ea5bbb934507fb00da9a0b7f
Reviewed-on: https://gem5-review.googlesource.com/7122
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Gabe Black <gabeblack@google.com>

src/cpu/exec_context.hh

@@ -222,19 +222,6 @@ class ExecContext {
      * @{
      * @name Memory Interface
      */
-    /**
-     * Record the effective address of the instruction.
-     *
-     * @note Only valid for memory ops.
-     */
-    virtual void setEA(Addr EA) = 0;
-    /**
-     * Get the effective address of the instruction.
-     *
-     * @note Only valid for memory ops.
-     */
-    virtual Addr getEA() const = 0;
-
     /**
      * Perform an atomic memory read operation.  Must be overridden
      * for exec contexts that support atomic memory mode.  Not pure