linux: kernel: add USB serial support and ACM class

linux: kernel: add USB serial support and ACM class

To allow for USB GPS devices the USB serial + ACM class need to
be enabled in the kernel.

Change-Id: I1b23b7d47bc49a3a61d5df5d964110023f91d481
Bug-AGL: SPEC-831
Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com>
Reviewed-on: https://gerrit.automotivelinux.org/gerrit/10681
Tested-by: Jenkins Job builder account <agl-jobbuilder@automotivelinux.org>
ci-image-build: Jenkins Job builder account <agl-jobbuilder@automotivelinux.org>
Reviewed-by: Matt Porter <mporter@konsulko.com>
Reviewed-by: José Bollo <jobol@nonadev.net>
Reviewed-by: Martin Kelly <mkelly@xevo.com>
Reviewed-by: Jan-Simon Moeller <jsmoeller@linuxfoundation.org>