cpuidle: tegra: Remove do_idle firmware call

The do_idle firmware call is unused by all Tegra SoCs, hence remove it in
order to keep driver's code clean.

Tested-by: Anton Bambura <[e-mail]> # TF701 T114
Tested-by: Matt Merhar <[e-mail]> # Ouya T30
Tested-by: Peter Geis <[e-mail]> # Ouya T30
Signed-off-by: Dmitry Osipenko <[e-mail]>
Reviewed-by: Daniel Lezcano <[e-mail]>
Signed-off-by: Daniel Lezcano <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

drivers/cpuidle/cpuidle-tegra.c

···
 static atomic_t tegra_idle_barrier;
 static atomic_t tegra_abort_flag;
 
-static inline bool tegra_cpuidle_using_firmware(void)
-{
-	return firmware_ops->prepare_idle && firmware_ops->do_idle;
-}
-
 static void tegra_cpuidle_report_cpus_state(void)
 {
 	unsigned long cpu, lcpu, csr;
···
 
 	err = call_firmware_op(prepare_idle, TF_PM_MODE_LP2_NOFLUSH_L2);
 	if (err && err != -ENOSYS)
-		return err;
-
-	err = call_firmware_op(do_idle, 0);
-	if (err != -ENOSYS)
 		return err;
 
 	return cpu_suspend(0, tegra30_pm_secondary_cpu_suspend);
···
 	 * is disabled.
 	 */
 	if (!IS_ENABLED(CONFIG_PM_SLEEP)) {
-		if (!tegra_cpuidle_using_firmware())
-			tegra_cpuidle_disable_state(TEGRA_C7);
-
+		tegra_cpuidle_disable_state(TEGRA_C7);
 		tegra_cpuidle_disable_state(TEGRA_CC6);
 	}