ata: libata: Add ata_force_get_fe_for_dev() helper

ata: libata: Add ata_force_get_fe_for_dev() helper

Add ata_force_get_fe_for_dev() helper to get the struct ata_force_ent for
a struct ata_device.

Use the helper in ata_force_quirks().
The helper will also be used in follow up commits.

No functional change intended.

Signed-off-by: Niklas Cassel <cassel@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>