sata_rcar: add 'base' local variable to some functions

The 'base' field of 'struct sata_rcar_priv' is used very often
throughout the driver, so it seems worth loading it into a local
variable if it's used more than once in a function.

While at it, put some unitialized variables after intialized ones for
aesthetic reasons. :-)

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Tejun Heo <tj@kernel.org>