Revert "xhci: Set HCD flag to defer primary roothub registration"

This reverts commit 0ea9ac73 which is
commit b7a0a792

 upstream.

It has been reported to be causing problems in Arch and Fedora bug
reports.

Reported-by: Hans de Goede <hdegoede@redhat.com>
Link: https://bbs.archlinux.org/viewtopic.php?pid=2000956#p2000956
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2019542
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2019576
Link: https://lore.kernel.org/r/42bcbea6-5eb8-16c7-336a-2cb72e71bc36@redhat.com
Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
Cc: Chris Chiu <chris.chiu@canonical.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>