ALSA: line6: Avoid polluting led_* namespace

led_colors clashes with the array of the same name being added
to the LED class. Do the following amendments to fix this issue
and the other prospective one.

led_colors -> toneport_led_colors
led_init_vals -> toneport_led_init_vals

Fixes: f44edd7b ("ALSA: line6/toneport: Implement LED controls via LED class")
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Takashi Iwai <tiwai@suse.de>