ata: libata-sata: Simplify sense_valid fetching

While the SENSE DATA VALID field in the ACS-6 specification is 47 bits,
we are currently only fetching 32 bits, because these are the only bits
that we care about (these bits represent the tags (which can be 0-31)).

Thus, replace the existing logic with a simple get_unaligned_le32().

While at it, change the type of sense_valid to u32.

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