fsl_sata: Fix compile error when CONFIG_LBA48 is not defined

If CONFIG_LBA48 is not defined, the element lba48 of struct sata_dev_desc
is not avaible, and can't be used.

Signed-off-by: Tang Yuantian <b29983@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>