clk: tegra: Use NULL for pointer initialization

This silences a sparse warning about using a plain integer instead of
NULL for a pointer.
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/tegra/clk-tegra210.c

@@ -2993,7 +2993,7 @@ static const char * const la_parents[] = {
 };
 
 static struct tegra_clk_periph tegra210_la =
-	TEGRA_CLK_PERIPH(29, 7, 9, 0, 8, 1, TEGRA_DIVIDER_ROUND_UP, 76, 0, NULL, 0);
+	TEGRA_CLK_PERIPH(29, 7, 9, 0, 8, 1, TEGRA_DIVIDER_ROUND_UP, 76, 0, NULL, NULL);
 
 static __init void tegra210_periph_clk_init(void __iomem *clk_base,
 					    void __iomem *pmc_base)