When printing, use a prefix of the PCI domain, bus, device and function
as in other drivers, to differentiate multiple devices.

Important for reporting and debugging. A future step is to tidy this up with
dev_printk et al.

v2: Move conversion specifier into call site, preventing build issues
v3: Refactor for Takashi's for-next branch
Signed-off-by: Daniel J Blueman <daniel@quora.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>