rust: pci: Fix a build system bug when PCI_MSI is not enabled

When enabling PCI without PCI_MSI, Rust pci code would fail to build. Fix this
by requiring both PCI and PCI_MSI to build Rust pci abstractions.

Reported-by: Philipp Stanner <pstanner@redhat.com>
Signed-off-by: Andreas Hindborg <a.hindborg@samsung.com>

rust/kernel/lib.rs

@@ -62,7 +62,7 @@ pub mod workqueue;
 #[doc(hidden)]
 pub use bindings;
 pub use macros;
-#[cfg(CONFIG_PCI)]
+#[cfg(all(CONFIG_PCI, CONFIG_PCI_MSI))]
 pub mod pci;
 pub use uapi;