hwspinlock: omap: Use devm_hwspin_lock_register() helper

This will unregister the HW spinlock on module exit automatically for us,
currently we manually unregister which can be error-prone if not done in
the right order. This also allows us to remove the remove callback.
Do that here.

Signed-off-by: Andrew Davis <afd@ti.com>
Link: https://lore.kernel.org/r/20240208165114.63148-3-afd@ti.com


Signed-off-by: Bjorn Andersson <andersson@kernel.org>