target/microblaze: Rename mmu structs

Introduce typedefs and follow CODING_STYLE for naming.
Rename struct microblaze_mmu to MicroBlazeMMU.
Rename struct microblaze_mmu_lookup to MicroBlazeMMULookup.

Tested-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
diff --git a/target/microblaze/helper.c b/target/microblaze/helper.c
index 27a24bb..3c2fd38 100644
--- a/target/microblaze/helper.c
+++ b/target/microblaze/helper.c
@@ -52,7 +52,7 @@
 {
     MicroBlazeCPU *cpu = MICROBLAZE_CPU(cs);
     CPUMBState *env = &cpu->env;
-    struct microblaze_mmu_lookup lu;
+    MicroBlazeMMULookup lu;
     unsigned int hit;
     int prot;
 
@@ -235,7 +235,7 @@
     MicroBlazeCPU *cpu = MICROBLAZE_CPU(cs);
     CPUMBState *env = &cpu->env;
     target_ulong vaddr, paddr = 0;
-    struct microblaze_mmu_lookup lu;
+    MicroBlazeMMULookup lu;
     int mmu_idx = cpu_mmu_index(env, false);
     unsigned int hit;