You can manually download and install it. The repos are not always updated right after new firmware is released.
When I run omreport (RHEL 7, PowerEdge T630, PERC H730p), it shows that the PERC controller is in a degraded state because it is running with Firmware Version 25.3.0.0016 and it claims the Minimum Required Firmware Version is 25.4.0.0011.  The latter has been withdrawn by Dell and this is known to the dsu command so that no upgrade is listed.  What needs to be done to convince omreport that the current recommended Firmware Version is actually 25.3.0.0016?
omreport uses withdrawn version for minimum required firmware of perc h730p