Use single module for clang runtime libraries

The clang prebuilts now provide a single module with per-architecture
variants instead of a module per architecture.

Bug: 220019988
Test: m checkbuild
Change-Id: I39e2cf8ae14edf8510276dab38011afaef85822c
diff --git a/rust/config/toolchain.go b/rust/config/toolchain.go
index a769f12..9c9d572 100644
--- a/rust/config/toolchain.go
+++ b/rust/config/toolchain.go
@@ -121,14 +121,7 @@
 }
 
 func LibclangRuntimeLibrary(t Toolchain, library string) string {
-	arch := t.LibclangRuntimeLibraryArch()
-	if arch == "" {
-		return ""
-	}
-	if !t.Bionic() {
-		return "libclang_rt." + library + "-" + arch
-	}
-	return "libclang_rt." + library + "-" + arch + "-android"
+	return "libclang_rt." + library
 }
 
 func LibRustRuntimeLibrary(t Toolchain, library string) string {