clk: tegra: Model oscillator as clock

Currently the Tegra clock driver simplifies the clock tree somewhat by
taking advantage of the fact that clk_m runs at the same frequency as
the oscillator. While that's true on all currently supported SoCs, it
does not apply to Tegra210 anymore. On Tegra210 clk_m is typically
divided down from the oscillator frequency. To support that setup, add
a separate clock for the oscillator that both clk_m and pll_ref derive
from.

Modify the tegra_osc_clk_init() function to take an additional divider
parameter for clk_m. Existing SoCs always pass in 1, whereas Tegra210
will read the divider from a register in the clock & reset controller.

Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers/clk/tegra/clk-tegra30.c

@@ -1434,7 +1434,8 @@ static void __init tegra30_clock_init(struct device_node *np)
 		return;
 
 	if (tegra_osc_clk_init(clk_base, tegra30_clks, tegra30_input_freq,
-		ARRAY_SIZE(tegra30_input_freq), &input_freq, NULL) < 0)
+			       ARRAY_SIZE(tegra30_input_freq), 1, &input_freq,
+			       NULL) < 0)
 		return;