Add --llndk to create_reference_dumps.py for llndk libraries.

Currently, we do abi checks on the system variants of llndk libraries.
Therefore, add an 'llndk' flag to specify that the system variant should be
built.

Bug: 77101345

Test: utils/create_reference_dumps.py --llndk -l libdl produces
      libdl references.

Change-Id: Id4c607674f096daf041520d4a1ca43199d4451da

vndk/tools/header-checker/utils/utils.py

@@ -136,12 +136,13 @@ def make_targets(targets, product):
     subprocess.check_call(make_cmd, cwd=AOSP_DIR, stdout=subprocess.DEVNULL,
                           stderr=subprocess.STDOUT)
 
-def make_libraries(libs, product):
+def make_libraries(libs, product, llndk_mode):
     # To aid creation of reference dumps. Makes lib.vendor for the current
     # configuration.
     lib_targets = []
     for lib in libs:
-        lib_targets.append(lib + VENDOR_SUFFIX)
+        lib = lib if llndk_mode else lib + VENDOR_SUFFIX
+        lib_targets.append(lib)
     make_targets(lib_targets, product)
 
 def find_lib_lsdumps(target_arch, target_arch_variant,