trace: add mmu_index to mem_info

We are going to re-use mem_info later for plugins and will need to
track the mmu_idx for softmmu code.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

scripts/tracetool/transform.py

@@ -83,6 +83,7 @@ TCG_2_HOST = {
 
 HOST_2_TCG_COMPAT = {
     "uint8_t": "uint32_t",
+    "uint16_t": "uint32_t",
     }