xhci: Expose segment numbers in debugfs

xhci: Expose segment numbers in debugfs

Ring segments have just been amended with a monotonically increasing
number.

To allow developers to inspect the segment numbers and ensure
correctness in particular after ring expansion, expose them in each
ring's "trbs" file in debugfs.

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20231019102924.2797346-9-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>