ARM: tegra: deduplicate MASK_BITS_xxx clock mux enum

The enum used to define the set of register bits used to represent a
clock's input mux, MUX_BITS_*, is defined separately for each SoC at
present. Move this definition to a common location to ease fixing up
some issues with the definition, and the code that uses it.

Signed-off-by: Tom Warren <twarren@nvidia.com>
[swarren, extracted from a larger patch by Tom]
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>

arch/arm/include/asm/arch-tegra/clock.h

@@ -20,6 +20,12 @@ enum clock_osc_freq {
 	CLOCK_OSC_FREQ_COUNT,
 };
 
+enum {
+	MASK_BITS_31_30	= 2,	/* num of bits used to specify clock source */
+	MASK_BITS_31_29,
+	MASK_BITS_29_28,
+};
+
 #include <asm/arch/clock-tables.h>
 /* PLL stabilization delay in usec */
 #define CLOCK_PLL_STABLE_DELAY_US 300