ata: libahci_platform: Remove bogus 32-bit DMA mask attempt

If 64-bit mask attempt fails, the 32-bit will fail by the very same reason.
Don't even try the latter. It's a continuation of the changes that contains,
e.g. dcc02c19 ("sata_sil24: use dma_set_mask_and_coherent").

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>