ice: Fix debugfs with devlink reload

During devlink reload it is needed to remove debugfs entries
correlated with only one PF. ice_debugfs_exit() removes all
entries created by ice driver so we can't use it.

Introduce ice_debugfs_pf_deinit() in order to release PF's
debugfs entries. Move ice_debugfs_exit() call to ice_module_exit(),
it makes more sense since ice_debugfs_init() is called in
ice_module_init() and not in ice_probe().

Signed-off-by: Wojciech Drewek <wojciech.drewek@intel.com>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
Reviewed-by: Brett Creeley <brett.creeley@amd.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>