aemfvp-a-rme: fix stack rebuild failure.

aemfvp-a-rme stack of last release fails when the stack is getting rebuilt
as there was a linux patch that we applied again causing error this
fix will check if the patch has been applied to the stack and won't
apply it again.

Signed-off-by: Ben Taylor <ben.taylor@linaro.org>
Change-Id: I7c01e260b39e28e98bda8d6aa18360e3c8f44d54