ARM: mach-shmobile: Kota2 SCIFA2 and SMSC911X support

Kota2 base board support including the on-chip SCIFA2
serial console and the on-board SMSC911X ethernet port.

The s73a0 SMP bits are also updated to include Kota2.

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