pmdomain: qcom: cpr: simplify main allocation

Remove kcalloc by using a flexible array member to combine allocations.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>