No.
From 2012 to SQL 2014 would be a problem (well, failover is fine, failback wouldn't be possible), but the service packs don't bump the internal DB version, so doesn't bother log shipping.
That said, you should patch the SP2 box sometime.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
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