ACPI: AC: Clean up printing messages

Replace the ACPI_DEBUG_PRINT() and ACPI_EXCEPTION() instances
in ac.c with acpi_handle_debug() and acpi_handle_info() calls,
respectively, which among other things causes the excessive log
level of the messages previously printed via ACPI_EXCEPTION() to
be increased.

Drop the _COMPONENT and ACPI_MODULE_NAME() definitions that are not
used any more, drop the no longer needed ACPI_AC_COMPONENT definition
from the headers and update the documentation accordingly.

While at it, replace the direct printk() invocation with pr_info(),
add a pr_fmt() definition to ac.c and drop the unneeded PREFIX
symbol definition from there.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>