UPSTREAM: xhci: dbc: Improve performance by removing delay in transfer event polling.

Queue event polling work with 0 delay in case there are pending transfers
queued up. This is part 2 of a 3 part series that roughly triples dbc
performace when using adb push and pull over dbc.

Max/min push rate after patches is 210/118 MB/s, pull rate 171/133 MB/s,
tested with large files (300MB-9GB) by Łukasz Bartosik

First performance improvement patch was commit 31128e74
("xhci: dbc: add dbgtty request to end of list once it completes")

Cc: Łukasz Bartosik <ukaszb@chromium.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20241227120142.1035206-2-mathias.nyman@linux.intel.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 03e3d9c2)

BUG=b:350022600
TEST=Verified adb push/pull performance is >100 MB/s
Change-Id: I9e78c3556ff4dbb4c3e43d5b0a16eedeaf36e299
Signed-off-by: Łukasz Bartosik <ukaszb@google.com>