Buildrom broken option USE_LZMA

[Myles Watson]

I'm not sure of the best way to fix this, but giving the user a choice of
whether to compress the payload using LZMA is not a good thing in v2, since
we don't have a way to modify the Config.lb or Config-lab.lb.

Having this option enabled for v2 means that half the possible configs are
broken.

There are a couple of ways to fix it:
1. Disable the option for v2 and choose whatever matches the chosen
Config.lb file
2. Add Config-lab-nolzma.lb Config-lab-lzma.lb Config-lzma.lb
Config-nolzma.lb files to every target
3. Add Config-1M-nolzma.lb etc files
4. Add Config-buildrom.lb files like Config-abuild.lb files with replaceable
__ROM_SIZE__ and __ENABLE_LZMA__ markers

Other ideas?

Thanks,
Myles