mesa: Update the bbappend to match oe-core
mesa: Update the bbappend to match oe-core

Make them specific to atmel layer so it can play well with rest of
BSP layers

Signed-off-by: Khem Raj <729d64b6f67515e258459a5f6d20ec88b2caf8df@gmail.com>

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