at91bootstrap: Add development recipe
at91bootstrap: Add development recipe

To follow the development of at91bootstrap and generate images based on
the latest revision, create a new recipe following Yocto Project
versioning guidelines : http://openembedded.org/wiki/Versioning_Policy

Signed-off-by: David Vincent <830c66fa9721c8442a57e7e099bc9fc78d2587f0@gmail.com>
[45b517be0e5ec6dc3a39715767c1d18e090d39b4@atmel.com: adapt to newer recipies, add weak priority]
Signed-off-by: Nicolas Ferre <45b517be0e5ec6dc3a39715767c1d18e090d39b4@atmel.com>

alexandrebelloni/meta-atmel,linux4sam/meta-atmel,linux4sam/meta-atmel,linux4sam/meta-atmel,alexandrebelloni/meta-atmel,koenkooi/meta-atmel,kraj/meta-atmel,kraj/meta-atmel,koenkooi/meta-atmel,linux4sam/meta-atmel,linux4sam/meta-atmel,koenkooi/meta-atmel,kraj/meta-atmel,alexandrebelloni/meta-atmel