github: Update contact info
github: Update contact info

Update with new mailing list and irc channel.

Signed-off-by: Sean V Kelley <2e220d3765e3e059981b3c8d241463f952b3ee5f@posteo.de>

01org/iotg-lin-gfx-va-driver,01org/iotg-lin-gfx-va-driver,01org/iotg-lin-gfx-va-driver,01org/iotg-lin-gfx-va-driver,01org/iotg-lin-gfx-va-driver