target-ppc: mmu_ctx_t should not be a global type

mmu_ctx_t is currently defined in cpu.h.  However it is used for temporary
information relating to mmu translation, and is only used in mmu_helper.c
and (now) mmu-hash{32,64}.c.  Furthermore it contains information which
should be specific to particular MMU types.  Therefore, move its definition
to mmu_helper.c.  mmu-hash{32,64}.c are converted to use new data types
private to the relevant MMUs (identical to mmu_ctx_t for now, but that will
change in future patches).

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>

target-ppc/mmu_helper.c

@@ -77,6 +77,19 @@ int cpu_ppc_handle_mmu_fault(CPUPPCState *env, target_ulong address, int rw,
 }
 
 #else
+
+/* Context used internally during MMU translations */
+typedef struct mmu_ctx_t mmu_ctx_t;
+struct mmu_ctx_t {
+    hwaddr raddr;      /* Real address              */
+    hwaddr eaddr;      /* Effective address         */
+    int prot;                      /* Protection bits           */
+    hwaddr hash[2];    /* Pagetable hash values     */
+    target_ulong ptem;             /* Virtual segment ID | API  */
+    int key;                       /* Access key                */
+    int nx;                        /* Non-execute area          */
+};
+
 /* Common routines used by software and hardware TLBs emulation */
 static inline int pte_is_valid(target_ulong pte0)
 {