Blades, unlike rack servers (who have default vnic and vHBA created), need to have vHBA defined in a service profile, which is then applied to the server.
https://www.cisco.com/c/en/us/td/docs/unified_computing/ucs/ucs-manager/GUI-User-Guides/Storage-Mgmt/4-0/b_UCSM_GUI_Storage_Management_Guide_4_0/b_UCSM_GUI_Storage_Management_Guide_4_0_chapter_010.html
https://www.cisco.com/c/en/us/td/docs/unified_computing/ucs/ucs-manager/videos/4-0/creating-a-vhba-template.html
Once you have adjusted your existing service profiles to contain vHBAs, and have rebooted the Blades to allow the change, the BIOS and OS on blade will detect new vHBA devices , and your ESXi host (assuming you correct Cisco fnic/nfnic vib/driver installed) should then see the fc hba device.
Actual connectivity for FC that includes zoning, vsan, etc, is separate discussion, but is covered in the UCSM admin guide referenced above.
Kirk...