Add CMA to the kernel arguments in uEnv.txt for U-Boot in images
with enabled feature agl-sota for software-over-the-air (SOTA)
updates for Raspberry Pi 3 B/B+.
Bug-AGL: SPEC-2729
Signed-off-by: Leon Anavi <leon.anavi@konsulko.com>
Change-Id: Id6914de6a41ebfd3fc28ca2948a15d891c9a30b3
(cherry picked from commit 86f76e0578b4cbb1a3b286b6e959e317866f9c31)