Put return parameter last and add more documentation.

This makes the parallel between mm_vm_identity_prepare and
mm_vm_identity_commit clearer.

Change-Id: Ieee0065ee1dd66648a85b03940a865ca84c06dc7
diff --git a/inc/hf/mm.h b/inc/hf/mm.h
index 69fa78a..1a0bfd6 100644
--- a/inc/hf/mm.h
+++ b/inc/hf/mm.h
@@ -108,11 +108,11 @@
 bool mm_vm_init(struct mm_ptable *t, struct mpool *ppool);
 void mm_vm_fini(struct mm_ptable *t, struct mpool *ppool);
 bool mm_vm_identity_map(struct mm_ptable *t, paddr_t begin, paddr_t end,
-			uint32_t mode, ipaddr_t *ipa, struct mpool *ppool);
+			uint32_t mode, struct mpool *ppool, ipaddr_t *ipa);
 bool mm_vm_identity_prepare(struct mm_ptable *t, paddr_t begin, paddr_t end,
 			    uint32_t mode, struct mpool *ppool);
 void mm_vm_identity_commit(struct mm_ptable *t, paddr_t begin, paddr_t end,
-			   uint32_t mode, ipaddr_t *ipa, struct mpool *ppool);
+			   uint32_t mode, struct mpool *ppool, ipaddr_t *ipa);
 bool mm_vm_unmap(struct mm_ptable *t, paddr_t begin, paddr_t end,
 		 struct mpool *ppool);
 bool mm_vm_unmap_hypervisor(struct mm_ptable *t, struct mpool *ppool);