[MIPS] Alchemy: SMBus resource fix

The Alchemy platform code registers the SMBus device using the virtual
address of its registers instead of the physical one -- fix this, taking
into account that actually the whole megabyte is decoded by any of the
programmable serial controllers (one of which is SMBus), and that all the
Alchemy peripherals are directly mappable into KSEG1 kernel space and
therefore ioremap() call would just boil down to CKSEG1ADDR() invocation.

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>