ALSA: echoaudio: Drop superfluous macro

Drop pci_device() macro that just leads to chip->pci->dev, and pass it
directly to request_firmware().  It was introduced for allowing the
external alsa-driver kernel module builds.  Since it was discontinued
years ago, we should clean it up now.

Signed-off-by: Takashi Iwai <tiwai@suse.de>