nfp: only clean `sp_indiff` when application firmware is unloaded

nfp: only clean `sp_indiff` when application firmware is unloaded

Currently `sp_indiff` is cleaned when driver is removed. This will
cause problem in multi-PF/multi-host case, considering one PF is
removed while another is still in use.

Since `sp_indiff` is the application firmware property, it should
only be cleaned when the firmware is unloaded. Now let management
firmware to clean it when necessary, driver only set it.

Fixes: b1e4f11e426d ("nfp: refine the ABI of getting `sp_indiff` info")
Signed-off-by: Yinjun Zhang <yinjun.zhang@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/20221020081411.80186-1-simon.horman@corigine.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>