[yocto] Meta layer for pine64

[Mont3z Claros]

Hi all,

I just finished a first beta version of a meta layer for SBC pine64.
You can find it in  https://github.com/mont3z/meta-pine64

I'd appreciate if anyone has any comments on possible improvements. A
major problem I had was the necessity of two toolchains: one for
compiling u-boot (32 bits) and another for compiling all other
components (64 bis). At the moment I have a very ugly hack to do it.
The 32 bit toolchain is an external toolchain and I set PATH
environmental variable in u-boot recipe.

Cheers,
Montez