softmmu: provide softmmu access type enum

New MIPS features depend on the access type and enum is more convenient than
using the numbers directly.

Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>

include/exec/cpu-common.h

@@ -26,6 +26,12 @@ typedef struct CPUListState {
     FILE *file;
 } CPUListState;
 
+typedef enum MMUAccessType {
+    MMU_DATA_LOAD  = 0,
+    MMU_DATA_STORE = 1,
+    MMU_INST_FETCH = 2
+} MMUAccessType;
+
 #if !defined(CONFIG_USER_ONLY)
 
 enum device_endian {