Blackfin: fix early crash when booting on wrong cpu

Make sure we process the kernel command line before poking the hardware,
so that we can process early printk.  This helps ensure that if you boot
a kernel configured for a different processor, something will be left in
the log buffer.

Signed-off-by: Robin Getz <robin.getz@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>