I feel the need to post this as an answer, even though it's really just a frame challenge.
Late edit*
As it appears the Homepod will come with a power adaptor, the job just got even cheaper, if just as simple.
Clip the cable anywhere it will be out of sight & join with a bit of terminal block, 50p from any DIY store.
It's designed for mains voltages, but to comply with regs, would need to be encased in a supporting/insulating block for 110/240v. For low-voltage DC you can leave it in the open, or wrap in a bit of insulating tape if you're a bit paranoid wary.
You're going to need to do this to get the cable through any inconspicuous hole in your desk/wall/ceiling anyway. If the plug at one end is proprietary or even a standard small-form figure-8, it's going to be much harder to achieve, plus user-fit figure 8s are more bulky than their moulded counterparts.
Replacing a standard mains plug is little more than a 5-minute job for anyone with an elementary skill-set. It will almost certainly be a double-insulated structure, so you've only two wires to get right. Brown live, blue neutral.