x86, olpc: Use pr_debug() for EC commands

Unconditionally printing EC debug messages was helpful when we were actually
debugging the EC, but during normal operation it can get pretty annoying.
Using pr_debug allows us finer-grained control.

Signed-off-by: Andres Salomon <dilinger@queued.net>
LKML-Reference: <20100616231928.16b539f0@dev.queued.net>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>