ACPI / EC: Convert all printk() calls to dynamic debug function

This patch is to convert all printks in the ec driver to pr_debug/info/err
and define pr_fmt macro to replace PREFIX.

Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>