ARM: mach-shmobile: Use SCIFA and SCIFB port types on sh7377

Update the sh7377 serial port types to make use of
PORT_SCIFA and PORT_SCIFB. This makes the software
match the sh7377 data sheet.

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