ALSA: usb-audio: Fix Scarlett 6i6 Gen 2 port data

ALSA: usb-audio: Fix Scarlett 6i6 Gen 2 port data

The s6i6_gen2_info.ports[] array had the Mixer and PCM port type
entries in the wrong place. Use designators to explicitly specify the
array elements being set.

Fixes: 9e4d5c1be21f ("ALSA: usb-audio: Scarlett Gen 2 mixer interface")
Signed-off-by: Geoffrey D. Bennett <g@b4.vu>
Tested-by: Alex Fellows <alex.fellows@gmail.com>
Tested-by: Markus Schroetter <project.m.schroetter@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20191110134356.GA31589@b4.vu
Signed-off-by: Takashi Iwai <tiwai@suse.de>