Enable J1939 support for qemu machines

Enable J1939 support for qemu machines

Tweak the can-bus.cfg kernel configuration fragment to set
CONFIG_CAN_J1939, and add an over-ride in the agl-service-can-low-level
recipe to enable J1939 support on qemu platforms where we know we have
a 5.4 kernel where it will work.

Bug-AGL: SPEC-3538

Signed-off-by: Scott Murray <scott.murray@konsulko.com>
Change-Id: I16e77a70794dd79ac37139dd19b15a9e131cbf3e
Reviewed-on: https://gerrit.automotivelinux.org/gerrit/c/AGL/meta-agl/+/25139
Tested-by: Jenkins Job builder account <agl-jobbuilder@automotivelinux.org>
ci-image-build: Jenkins Job builder account <agl-jobbuilder@automotivelinux.org>
ci-image-boot-test: Jenkins Job builder account <agl-jobbuilder@automotivelinux.org>
Reviewed-by: Jan-Simon Moeller <jsmoeller@linuxfoundation.org>