media: ti-vpe: cal: Inline cal_data_get_num_csi2_phy() in its caller
The cal_data_get_num_csi2_phy() function simply returns
cal->data->num_csi2_phy, and is not consistently used across the driver,
as most accesses to cal->data->num_csi2_phy are open-coded. We could fix
those open-coded accesses to use cal_data_get_num_csi2_phy(), but that
wouldn't bring much in terms of readability, so inline
cal_data_get_num_csi2_phy() in its only caller instead, and drop the
function.