QEMU spapr/pseries honors -boot once=d / order=, so leaving
$arch_supports_boot_order disabled on ppc64le made install tests
that supply both an ISO and an HDD_1 boot the HDD instead of the
installer CD (same symptom as running x86_64 without -boot). Drop
that line from the patch so ppc64le behaves like x86_64.
Patch description updated to record the history; hunk shrinks by
one line and the patch diffstat updates accordingly.
Patch by Elkhan Mammadli <elkhan.mammadli@protonmail.com>. Adjusts the
QEMU backend for the QEMU build shipped in Enterprise Linux on AArch64
and ppc64le: use qemu-xhci on AArch64, wire virtio keyboard/tablet on
ppc64le, disable audio, and skip unsupported boot-order and floppy
handling.
