tegra: Correct PLL access in ap20.c and clock.c

Correct this warning seen by Albert:

ap20.c:44:18: warning: array subscript is above array bounds

There is a subtle bug here which currently causes no errors, but might
in future if people use PCI or the 32KHz clock. So take the opportunity
to correct the logic now.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
diff --git a/arch/arm/include/asm/arch-tegra2/clock.h b/arch/arm/include/asm/arch-tegra2/clock.h
index 1d3ae38..ff83bbf 100644
--- a/arch/arm/include/asm/arch-tegra2/clock.h
+++ b/arch/arm/include/asm/arch-tegra2/clock.h
@@ -186,8 +186,9 @@
 /* Mask value for a clock (within PERIPH_REG(id)) */
 #define PERIPH_MASK(id) (1 << ((id) & 0x1f))
 
-/* return 1 if a PLL ID is in range */
-#define clock_id_isvalid(id) ((id) >= CLOCK_ID_FIRST && (id) < CLOCK_ID_COUNT)
+/* return 1 if a PLL ID is in range, and not a simple PLL */
+#define clock_id_is_pll(id) ((id) >= CLOCK_ID_FIRST && \
+		(id) < CLOCK_ID_FIRST_SIMPLE)
 
 /* PLL stabilization delay in usec */
 #define CLOCK_PLL_STABLE_DELAY_US 300