clk: tegra30: Use Tegra CPU powergate helper function

Rather than using the tegra_powergate_is_powered() function for
determining if a CPU is powered, use the tegra_pmc_cpu_is_powered()
instead which was created to get the CPU power status. Internally
tegra_pmc_cpu_is_powered() calls tegra_powergate_is_powered() and so
is equivalent.

The Tegra30 clock driver is the only public user of
tegra_powergate_is_powered() and so by updating the Tegra30 clock
driver to use tegra_pmc_cpu_is_powered(), we can then make
tegra_powergate_is_powered() a non-public function.
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/tegra/clk-tegra30.c

@@ -1148,9 +1148,9 @@ static bool tegra30_cpu_rail_off_ready(void)
 
 	cpu_rst_status = readl(clk_base +
 				TEGRA30_CLK_RST_CONTROLLER_CPU_CMPLX_STATUS);
-	cpu_pwr_status = tegra_powergate_is_powered(TEGRA_POWERGATE_CPU1) ||
-			 tegra_powergate_is_powered(TEGRA_POWERGATE_CPU2) ||
-			 tegra_powergate_is_powered(TEGRA_POWERGATE_CPU3);
+	cpu_pwr_status = tegra_pmc_cpu_is_powered(1) ||
+			 tegra_pmc_cpu_is_powered(2) ||
+			 tegra_pmc_cpu_is_powered(3);
 
 	if (((cpu_rst_status & 0xE) != 0xE) || cpu_pwr_status)
 		return false;