rust: add ccToolchain to Module

The cc toolchain information is required when using cc.Stripper.
Move to a Module method to avoid importing the cc package everywhere.

Test: m nothing
Bug: 153430439
Change-Id: I497dcdff4e767ecb8b8688c73cf88850c302683d
diff --git a/rust/bindgen.go b/rust/bindgen.go
index 9b09e61..3f7a6ce 100644
--- a/rust/bindgen.go
+++ b/rust/bindgen.go
@@ -21,7 +21,6 @@
 	"github.com/google/blueprint/proptools"
 
 	"android/soong/android"
-	ccConfig "android/soong/cc/config"
 )
 
 var (
@@ -92,8 +91,8 @@
 	Properties BindgenProperties
 }
 
-func (b *bindgenDecorator) GenerateSource(ctx android.ModuleContext, deps PathDeps) android.Path {
-	ccToolchain := ccConfig.FindToolchain(ctx.Os(), ctx.Arch())
+func (b *bindgenDecorator) GenerateSource(ctx ModuleContext, deps PathDeps) android.Path {
+	ccToolchain := ctx.RustModule().ccToolchain(ctx)
 
 	var cflags []string
 	var implicits android.Paths