fsl_sata: Fix compiler warnings shown by gcc-4.4

Update fsl_sata to use common structures instead of casting
back and forth between the fsl specific ones and the common ones
(which are identical).

fsl_sata.c: In function 'scan_sata':
fsl_sata.c:550: warning: dereferencing pointer 'cfis' does break strict-aliasing rules
fsl_sata.c:549: warning: dereferencing pointer 'cfis' does break strict-aliasing rules
fsl_sata.c:548: warning: dereferencing pointer 'cfis' does break strict-aliasing rules
fsl_sata.c:545: note: initialized from here
fsl_sata.c:592: warning: dereferencing pointer 'cfis' does break strict-aliasing rules
fsl_sata.c:590: warning: dereferencing pointer 'cfis' does break strict-aliasing rules
fsl_sata.c:588: warning: dereferencing pointer 'cfis' does break strict-aliasing rules
fsl_sata.c:586: warning: dereferencing pointer 'cfis' does break strict-aliasing rules
fsl_sata.c:579: warning: dereferencing pointer 'cfis' does break strict-aliasing rules
...

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>