Hi,
Pretty much what Mohieddin said, but I will add a little bit to it.
The one important difference between HP and Cisco 802.1Q implementation is that HP ports have the tagged and untagged ports explicitly defined, while at its most basic, Cisco ports are either in access mode or trunk mode. Access mode effectively has nothing tagged and one vlan untagged. Trunk mode by default has VLAN 1 traffic untagged and will pass ANY tagged traffic. You can change this behavior, limit the VLANS that it will work with, but by default,
Cisco(config-if)#switchport trunk encap dot1q
Cisco(config-if)#switchport mode trunk
will let EVERYTHING through -- so that would be the minimal configuration to get it to work.
If your default vlan is not VLAN 1 then you will need to use
switchport trunk native vlan xxx
This is the Cisco equivalent of having that VLAN untagged, but since the port is in Trunk mode it tags everything else. This is also useful if the management interface for the AP is not on VLAN 1.
Good luck! Hopefully I've been at least somewhat clear in my description above.