pvmfw: Add swiotlb <reg> to platform.dts

Instead of inserting the property into the template DT (which requires
shifting all following nodes), have a placeholder property that can be
overwritten in place.

Ensure that it is removed (NOP-ed) when not required.

Test: m pvmfw_img
Change-Id: Ife13eb84e23c43655513dfedffdedb1ea7fd2e78
diff --git a/libs/libfdt/Android.bp b/libs/libfdt/Android.bp
index 72399b0..5a729f1 100644
--- a/libs/libfdt/Android.bp
+++ b/libs/libfdt/Android.bp
@@ -37,6 +37,7 @@
     ],
     rustlibs: [
         "liblibfdt_bindgen",
+        "libzerocopy_nostd",
     ],
     whole_static_libs: [
         "libfdt",