ata: libata-core: Set ATA_QCFLAG_RTF_FILLED in fill_result_tf()

ATA_QCFLAG_RTF_FILLED is not specific to ahci and can be used generally
to check if qc->result_tf contains valid data.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Igor Pylypiv <ipylypiv@google.com>
Link: https://lore.kernel.org/r/20240702024735.1152293-7-ipylypiv@google.com


Signed-off-by: Niklas Cassel <cassel@kernel.org>