tegra20: add clock_set_pllout function

Common practice on Tegra 2 boards is to use the pllp_out4 FO
to generate the ULPI reference clock. For this to work we have
to override the default hardware generated output divider.

This function adds a clean way to do so.

Signed-off-by: Lucas Stach <dev@lynxeye.de>
Signed-off-by: Tom Warren <twarren@nvidia.com>
diff --git a/arch/arm/include/asm/arch-tegra20/clock-tables.h b/arch/arm/include/asm/arch-tegra20/clock-tables.h
index f2b2769..53708e0 100644
--- a/arch/arm/include/asm/arch-tegra20/clock-tables.h
+++ b/arch/arm/include/asm/arch-tegra20/clock-tables.h
@@ -176,6 +176,13 @@
 	PERIPH_ID_NONE = -1,
 };
 
+enum pll_out_id {
+	PLL_OUT1,
+	PLL_OUT2,
+	PLL_OUT3,
+	PLL_OUT4
+};
+
 /* Converts a clock number to a clock register: 0=L, 1=H, 2=U */
 #define PERIPH_REG(id) ((id) >> 5)