spi: orion: fix runtime pm leak on unbind

spi: orion: fix runtime pm leak on unbind

Make sure to balance the runtime PM usage count on driver unbind so that
the controller can be suspended when a driver is rebound.

Also restore the autosuspend setting.

This issue was flagged by Sashiko when reviewing a controller
deregistration fix.

Fixes: 5c6786945b4e ("spi: spi-orion: add runtime PM support")
Cc: stable@vger.kernel.org	# 3.17
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Link: https://sashiko.dev/#/patchset/20260414134319.978196-1-johan%40kernel.org?part=6
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://patch.msgid.link/20260421130211.1537628-2-johan@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>