fbdev: au1100fb: Replace custom printk wrappers by pr_*

fbdev: au1100fb: Replace custom printk wrappers by pr_*

The global wrappers also have the advantage to do stricter format
checking, so the pr_devel formats are also checked if DEBUG is not
defined. The global variants only check for DEBUG being defined and not
its actual value, so the #define to zero is dropped, too.

There is only a slight semantic change as the (by default disabled)
debug output doesn't contain __FILE__ any more.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Signed-off-by: Helge Deller <deller@gmx.de>