Instead of calling printk() directly, use pr_foo()
macros, as suggested at the Kernel's coding style.

Please notice that a conversion to dev_foo() is not trivial,
as several parts on this driver uses pr_cont().
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>