runqemu-internal: add "console=ttyS0" to ramfs image kernel parameters

runqemu-internal: add "console=ttyS0" to ramfs image kernel parameters

We need this kernel command parameter so that when we start a ramfs
image, we can actually get some output. Although we can make this
happen by specifying the 'bootparams' for the 'runqemu' command, it's
better to make this the default behaviour.

(From OE-Core rev: 3d202594bb92fe75cd70f81345e64c2179b52c32)

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>