kernel-resin.bbclass: Enable CONFIG_USB_ACM as module by default
kernel-resin.bbclass: Enable CONFIG_USB_ACM as module by default

Fixes #1033

Change-type: patch
Changelog-entry: USB Modem (CDC ACM) support enabled as kernel module
Signed-off-by: Andrei Gherzan <8dc7c09356db0b1762fb140617d7375c0a5a4131@resin.io>

resin-os/meta-resin,resin-os/meta-resin,resin-os/meta-resin,resin-os/meta-resin