This allows the baud rate for earlyprintk for sh4 without the
standard BIOS to be set via the command line. This uses the same
format as i386 and x86_64, which is:

	earlyprintk=serial,ttySC1,38400

The second parameter (ttySC1 above) is usually the console device
name or the io address of the serial port. I allow that to be
specified but ignore it in order to keep the format the same as
i386/x86_64.
Signed-off-by: NJamie Lenehan <lenehan@twibble.org>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>