at91: fixed plla calc when no USB support is active

Signed-off-by: Daniel Gorsulowski <Daniel.Gorsulowski@esd.eu>
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>

cpu/arm926ejs/at91/clock.c

diff --git a/cpu/arm926ejs/at91/clock.c b/cpu/arm926ejs/at91/clock.c
index 31e53b3..f776f70 100644
--- a/cpu/arm926ejs/at91/clock.c
+++ b/cpu/arm926ejs/at91/clock.c
@@ -126,6 +126,7 @@
 fail:
 	return 0;
 }
+#endif
 
 static u32 at91_pll_rate(u32 freq, u32 reg)
 {
@@ -141,7 +142,6 @@
 
 	return freq;
 }
-#endif
 
 int at91_clock_init(unsigned long main_clock)
 {