ALSA: usb-audio: Use lower hex numbers for IDs

For consistency reason, make all hex numbers with lower alphabets for
USB ID entries.  It improves grep-ability and reduces careless
mistakes.

Link: https://lore.kernel.org/r/20200105081900.21870-1-tiwai@suse.de


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