SQL 2005 SP2 Database on SQL 2012 Instance
The Compatibility Level never changes due to a Service Pack upgrade. So SP4 has the same Compatibility Level as SP2, same features and limitations etc, it's just presumably better/faster/more stable/more secure. 

SQL2005 databases have Level 90 (unless they were restored from even older versions without updating the Level) and can be restored on SQL 2005 through 2012.

For the complete table of SQL Server versions vs supported Compatibility Levels, see:
https://docs.microsoft.com/en-us/sql/t-sql/statements/alter-database-transact-sql-compatibility-level