Neither, or both, your system has two single port pci adapters and an onboard dual port adapter:
P1-T9 and T10 are onboard (no Cx number) so not pci cards but built into the planar, as the preceding U787B.001.DNWFVCH is the same they are on the same planar / system board.
Both ent1 and ent2 are at location 07 = onboard and as they have the same major location of 07 this is a dual port adapter but as there is no Cx number they are onboard they are not in a pci slot.
P1-C5 indicates from the C5 bit that this is a card in a pci slot number 5, again the preceding U787B.001.DNWFVCH is the same so it is in / on the same planar / system board.
P1-C2 indicates from the C2 bit that this is a card in a pci slot number 2, again the preceding U787B.001.DNWFVCH is the same so it is in / on the same planar / system board.
The AIX location gives us the controller addresses so ent0 is on pci controller at location 06 = pci slot 5 and ent3 is on pci controller at location 0A = pci slot 2.
So you have two built in ethernet interfaces and the other two are on pci cards, ent0 in slot 5 (C5) and ent3 in pci slot 2 (C2).
All are Base-TX, so copper not fibre, gigabit adapters.
eth0 and 3 would seem from the description "10/100/1000 Base-TX PCI-X Adapter (14106902)" to be these guys:
IBM
HTH, Please explain if you need more info / clarification.
For example if you need two NIB etherchannels go for a pci card with a onboard for backup and the same or reversed for the other etherchannel.
Don't put both onboard in the same etherchannel because if the dual port chip fails you will lose the etherchannel.
Regards,
Duke.