Merge pull request #108 from stm32-rs/field_access_fix

empty field access

Author: burrbull

src/patch/register.rs

@@ -239,6 +239,9 @@ impl RegisterExt for Register {
             }
             // For all other tags, just set the value
             ftag.modify_from(make_field(fmod)?, VAL_LVL)?;
+            if let Some("") = fmod.get_str("access")? {
+                ftag.access = None;
+            }
         }
         Ok(())
     }