rust.inc: include missing dependency on gcc-cross

-cross recipes do not automatically depend on gcc-cross, but rust
definitely needs it.

recipes/rust/rust.inc

@@ -381,6 +381,7 @@ USE_LOCAL_RUST_class-native ?= "${@base_conditional('USE_LOCAL_NATIVE_RUST', '0'
 # Otherwise we'll depend on what we provide
 INHIBIT_DEFAULT_RUST_DEPS_class-cross = "1"
 DEPENDS_class-cross += "rust-native"
+DEPENDS_class-cross += "gcc-cross"
 PROVIDES_class-cross = "virtual/${TARGET_PREFIX}rust"
 PN_class-cross = "rust-cross-${TARGET_ARCH}"