gate CAN so L412/L422 can be part of CI

Crzyrndm · Crzyrndm · commit 2886de19a648 · 2021-12-04T11:25:45.000+13:00
diff --git a/Cargo.toml b/Cargo.toml
@@ -142,7 +142,7 @@ required-features = ["rt"]
 
 [[example]]
 name = "can-loopback"
-required-features = ["rt"]
+required-features = ["rt", "stm32l433" ] # CAN peripheral on ever series except L41/L42, gate so CI will pass
 
 [[example]]
 name = "irq_button"
