liblibfdt: Add no_std variant for libfdt_baremetal

Add a second rlib that wraps the newly-created libfdt_baremetal
cc_library to ensure that baremetal clients (using the *_nostd library
variants) don't use the non-_baremetal C library. This allows baremetal
code to be compiled with a different set of Clang flags.

Test: m pvmfw
Change-Id: I71b50eeafe257fa6086805ca5a6b4c0de935bb32
diff --git a/guest/rialto/Android.bp b/guest/rialto/Android.bp
index 4c18bf9..eeb5b2d 100644
--- a/guest/rialto/Android.bp
+++ b/guest/rialto/Android.bp
@@ -15,7 +15,7 @@
         "libcstr",
         "libdiced_open_dice_nostd",
         "libfdtpci",
-        "liblibfdt",
+        "liblibfdt_nostd",
         "liblog_rust_nostd",
         "libservice_vm_comm_nostd",
         "libservice_vm_fake_chain_nostd",