ALSA: line6: update contact information

The Line6 driver source code files contain an outdated email address of the
original author. This patch updates the contact information.

Signed-off-by: Markus Grabner <line6@grabner-graz.at>
Link: https://patch.msgid.link/20241009194251.15662-1-line6@grabner-graz.at


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