xhci(4): Describe AMD 400 Series USB 3.1 controllers

While at it, correct the string for 300 series ones, these also are
already xHCI 3.1.

Fixes: d171d2f2 Add AHCI/XHCI device IDs found on AMD Ryzen+B350 system
(cherry picked from commit 83e67a9d14d9cf3830cd52f4f49117bf7220ac49)