Add soft float package to Linaro Ubuntu rootfs

[Fathi Boudra]

Initially reported by Rony:

I suggest two additional features for Quantal based root filesystem:

* Our server rootfs is compiled with hard float and has no soft float support.
I was evaluating some middleware that can only be run using some additional soft float libraries.
The solution was to install libc6-armel libsfgcc1 libsfstdc++6 packages.

Please include those libraries in the rootfs so that middleware with softfloat support can also run.

* The stock native gcc toolchain in the filesystem is hardfloat. But some middleware can't be built using hardfloat due to software limitations in them. To natively build them armel native tool chain is required.
It might be a good idea to include the armel (softfloat) also as part of the filesystem.

Please add gcc armel as a part of the rootfs.