Revert "regmap: detach regmap from dev on regmap_exit"

This reverts commit f373a189 which is
commit 3061e170 upstream.

It was backported incorrectly, a fixed version will be applied later.

Cc: Cosmin Tanislav <demonsingur@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20250115033244.2540522-1-tzungbi@kernel.org


Reported-by: Tzung-Bi Shih <tzungbi@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>