FROMGIT: xhci: sideband: add initial api to register a secondary interrupter entity

Introduce XHCI sideband, which manages the USB endpoints being requested by
a client driver.  This is used for when client drivers are attempting to
offload USB endpoints to another entity for handling USB transfers.  XHCI
sec intr will allow for drivers to fetch the required information about the
transfer ring, so the user can submit transfers independently.  Expose the
required APIs for drivers to register and request for a USB endpoint and to
manage XHCI secondary interrupters.

Driver renaming, multiple ring segment page linking, proper endpoint clean
up, and allowing module compilation added by Wesley Cheng to complete
original concept code by Mathias Nyman.

Tested-by: Puma Hsu <pumahsu@google.com>
Tested-by: Daehwan Jung <dh10.jung@samsung.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Co-developed-by: Wesley Cheng <quic_wcheng@quicinc.com>
Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
Acked-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20250409194804.3773260-2-quic_wcheng@quicinc.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Bug: 392112015
(cherry picked from commit de66754e
 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git

 usb-next)
Change-Id: I10f8dedefd413aa8f7885884940890489a68235d
Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>