staging: speakup: fix printk KERN_LEVEL facility level warning

Replace printk with pr_info to solve checkpatch.pl warning:
 " WARNING: printk() should include  KERN_<LEVEL> facility level"

Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>