ALSA: scarlett2: Add support for Solo, 2i2, and 4i4 Gen 4

Add new Focusrite Scarlett Gen 4 USB IDs, notification arrays, config
sets, and device info data.

Signed-off-by: Geoffrey D. Bennett <g@b4.vu>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/b33526d3b7a56bb2c86aa4eb2137a415bd23f1ce.1703612638.git.g@b4.vu