abituguru: Add suspend/resume support

This patch contains rudimentary suspend / resume support for the uguru,
this protects the uguru and the driver against suspend / resume cycles,
so there is no reason to unload the driver in your suspend / resume
scripts.

Only include suspend / resume functions when CONFIG_PM is set.

Signed-off-by: Hans de Goede <j.w.r.degoede@hhs.nl>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>