arm64: msm8996: fix memory region overlap

This patch fixes memory region overlap between adsp and gpu.

Fix this by reusing the slpi memory region for gpu zap shader.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Ondrej Kubik <ondrej.kubik@canonical.com>