sdbus++: fix enumeration property default values

Current generation emits for enumerations:
    Enum property = EnumValue
Fix this to be:
    Enum property = Enum::EnumValue

Change-Id: Iae1e8e4ad73bf8623ed9f3b2d3ec57803c7f18bd
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
2 files changed