ci: test more specific variants of examples

[Ivan-Velickovic]

We need to be able to get the CI scripts to build certain extra configurations for certain platforms and then test those images.

This is needed so we can check the block example works with the NVMe driver, e.g in the case of QEMU our default driver is virtIO block but it would be ideal to test both virtIO block and NVMe.

[JDuchniewicz]

How do you get the blk driver to build with NVMe driver? I tried passing NVME=1 to make command but no success. We could extend the matrix with driver overrides and then generate multiple configurations as we do with build systems.

Also it seems like the verbose command does not print itself properly, that's what is printed for me:

python3 \
	/home/jduchniewicz/Projects/UNSW/sddf/examples/blk/meta.py --sddf /home/jduchniewicz/Projects/UNSW/sddf --board qemu_virt_aarch64 \
	--dtb qemu_virt_aarch64.dtb --output . --sdf blk.system  \
	${BLK_NEED_TIMER:+--need_timer} \
	${NVME:+--nvme}

[Ivan-Velickovic]

NVME=1 only works with x86_64_generic currently.

@dumsum can you add a section to the block example README with a title something like 'Testing with other block drivers' and then example NVMe is an option right now but only for x86_64_generic.

[Ivan-Velickovic]

@dumsum can you add a section to the block example README with a title something like 'Testing with other block drivers' and then example NVMe is an option right now but only for x86_64_generic.

Done in 544bc7c.