kbuild: rust: allow modules to allocate memory

The `allocator_api` feature is needed by drivers that allocate memory.

Signed-off-by: Wedson Almeida Filho <[email protected]>

Author: wedsonaf

scripts/Makefile.build

@@ -262,7 +262,7 @@ $(obj)/%.lst: $(src)/%.c FORCE
 # Compile Rust sources (.rs)
 # ---------------------------------------------------------------------------
 
-rust_allowed_features := new_uninit,return_position_impl_trait_in_trait,offset_of
+rust_allowed_features := new_uninit,return_position_impl_trait_in_trait,offset_of,allocator_api
 
 # `--out-dir` is required to avoid temporaries being created by `rustc` in the
 # current working directory, which may be not accessible in the out-of-tree