"to patch things up" means "to fix things" It could be meant literally, referring to fixing items of snagging or maintenance. Or maybe it could be meant figuratively, referring to reconciliation.

In this case it means to improve or restore a relationship damaged by a disagreement or dispute. However, there are two other meanings which are to: 1. Mend or repair something in order to make it functional again. 2. Treat someone’s wound or injury.