sh: sh4 scif pdata (sh7750/sh7760/sh4-202)

This patch breaks out the sh4 scif serial port platform
data from a shared platform device to one platform
device per port. Also, add serial ports to the list of
early platform devices.

While at it, get rid of the R2D ifdef in the processor
code and adjust the defconfigs to use ttySC1.

Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>