ACPI: dock: Send key=value pair instead of plain value

Send key=value pair along with the uevent instead of a plain value so that
userspace (udev) can handle it like common environment variables.

Signed-off-by: Holger Macht <hmacht@suse.de>
Acked-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Cc: Stephan Berberig <s.berberig@arcor.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>