clknode_get_parent_idx
p_idx = clknode_get_parent_idx(clk);
p_idx = clknode_get_parent_idx(clk);
int clknode_get_parent_idx(struct clknode *clk);
p_idx = clknode_get_parent_idx(clk);
p_idx = clknode_get_parent_idx(clk);