clk: mediatek: clk-mt6779: Add check for mtk_alloc_clk_data

Add the check for the return value of mtk_alloc_clk_data() in order to
avoid NULL pointer dereference.

Fixes: 710774e04861 ("clk: mediatek: Add MT6779 clock support")
Signed-off-by: Jiasheng Jiang <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Reviewed-by: AngeloGioacchino Del Regno <[e-mail]>
Signed-off-by: Stephen Boyd <[e-mail]>

drivers/clk/mediatek/clk-mt6779.c

···
 	struct device_node *node = pdev->dev.of_node;
 
 	clk_data = mtk_alloc_clk_data(CLK_APMIXED_NR_CLK);
+	if (!clk_data)
+		return -ENOMEM;
 
 	mtk_clk_register_plls(node, plls, ARRAY_SIZE(plls), clk_data);
 
···
 		return PTR_ERR(base);
 
 	clk_data = mtk_alloc_clk_data(CLK_TOP_NR_CLK);
+	if (!clk_data)
+		return -ENOMEM;
 
 	mtk_clk_register_fixed_clks(top_fixed_clks, ARRAY_SIZE(top_fixed_clks),
 				    clk_data);