interconnect: qcom: Fix icc_onecell_data allocation

This is a struct with a trailing zero-length array of icc_node pointers
but it's allocated as if it were a single array of icc_nodes instead.

This allocates too much memory at probe time but shouldn't have any
noticeable effect. Both sdm845 and qcs404 are affected.

Fix by replacing kcalloc with kzalloc and using the "struct_size" macro.

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Fixes: 5e4e6c4d ("interconnect: qcom: Add QCS404 interconnect provider driver")
Link: https://lore.kernel.org/linux-pm/a7360abb6561917e30bbfaa6084578449152bf1d.1569348056.git.leonard.crestez@nxp.com/


Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>