clk: tegra: Use readl_relaxed_poll_timeout_atomic() in tegra210_clock_init()

Below is the call trace of tegra210_init_pllu() function:
  start_kernel()
  -> time_init()
  --> of_clk_init()
  ---> tegra210_clock_init()
  ----> tegra210_pll_init()
  -----> tegra210_init_pllu()

Because the preemption is disabled in the start_kernel before calling
time_init, tegra210_init_pllu is actually in an atomic context while
it includes a readl_relaxed_poll_timeout that might sleep.

So this patch just changes this readl_relaxed_poll_timeout() to its
atomic version.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Acked-By: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers/clk/tegra/clk-tegra210.c

@@ -2568,8 +2568,8 @@ static int tegra210_enable_pllu(void)
 	reg |= PLL_ENABLE;
 	writel(reg, clk_base + PLLU_BASE);
 
-	readl_relaxed_poll_timeout(clk_base + PLLU_BASE, reg,
-				   reg & PLL_BASE_LOCK, 2, 1000);
+	readl_relaxed_poll_timeout_atomic(clk_base + PLLU_BASE, reg,
+					  reg & PLL_BASE_LOCK, 2, 1000);
 	if (!(reg & PLL_BASE_LOCK)) {
 		pr_err("Timed out waiting for PLL_U to lock\n");
 		return -ETIMEDOUT;