Fix for invalid use of bits in input context. Basically split
configuring of EP0 and non-EP0 into xhci_cmd_evaluate_ctx() and
xhci_cmd_configure_ep() respectivly. This resolves some errors when
using XHCI under QEMU and gets is more in line with the XHCI
specification.

PR: 212021
MFC after: 1 week