qed: Remove unused qed_db_recovery_dp

qed_db_recovery_dp() was added in 2018 as part of
commit 36907cd5 ("qed: Add doorbell overflow recovery mechanism")
but has remained unused.

Remove it.

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Link: https://patch.msgid.link/20250414005247.341243-6-linux@treblig.org


Signed-off-by: Jakub Kicinski <kuba@kernel.org>