arch/arm/cpu/armv7/omap-common/clocks-common.c: Fix build warnings

Fix:
clocks-common.c: In function 'setup_non_essential_dplls':
clocks-common.c:323:6: warning: variable 'sys_clk_khz' set but not used
[-Wunused-but-set-variable]
clocks-common.c: In function 'setup_non_essential_dplls':
clocks-common.c:323:6: warning: variable 'sys_clk_khz' set but not used
[-Wunused-but-set-variable]

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Cc: Tom Rini <trini@ti.com>
diff --git a/arch/arm/cpu/armv7/omap-common/clocks-common.c b/arch/arm/cpu/armv7/omap-common/clocks-common.c
index 4cfe119..4e74569 100644
--- a/arch/arm/cpu/armv7/omap-common/clocks-common.c
+++ b/arch/arm/cpu/armv7/omap-common/clocks-common.c
@@ -320,11 +320,9 @@
 #ifdef CONFIG_SYS_CLOCKS_ENABLE_ALL
 static void setup_non_essential_dplls(void)
 {
-	u32 sys_clk_khz, abe_ref_clk;
+	u32 abe_ref_clk;
 	const struct dpll_params *params;
 
-	sys_clk_khz = get_sys_clk_freq() / 1000;
-
 	/* IVA */
 	clrsetbits_le32(&prcm->cm_bypclk_dpll_iva,
 		CM_BYPCLK_DPLL_IVA_CLKSEL_MASK, DPLL_IVA_CLKSEL_CORE_X2_DIV_2);