[TEMP] config/rdfremont: switch to gcc 10 aarch64-none-linux

KVM tool built with GCC 11 aarch64-none-linux is expecting glibc-2.34
from buildroot, but buildroot latest (as of with 2022.08 tag) builds
only glibc-2.33. This leads to failure to launch the lkvm tool from
buildroot. As a workaround, use GCC 10 instead of GCC 11.

Signed-off-by: Vijayenthiran Subramaniam <vijayenthiran.subramaniam@arm.com>
Change-Id: I7b915a74a7ed42509ad2831727e9b56fedffef77