arch/arm/cpu/armv7/s5p-common/pwm.c: fix GCC 4.6 warning

Fix:
pwm.c: In function 'pwm_config':
pwm.c:85:16: warning: variable 'timer_rate_hz' set but not used
[-Wunused-but-set-variable]

Signed-off-by: Anatolij Gustschin <agust@denx.de>

arch/arm/cpu/armv7/s5p-common/pwm.c

@@ -82,7 +82,6 @@ int pwm_config(int pwm_id, int duty_ns, int period_ns)
 	unsigned long period;
 	unsigned long tcon;
 	unsigned long tcnt;
-	unsigned long timer_rate_hz;
 	unsigned long tcmp;
 
 	/*
@@ -100,7 +99,6 @@ int pwm_config(int pwm_id, int duty_ns, int period_ns)
 
 	/* Check to see if we are changing the clock rate of the PWM */
 	tin_rate = pwm_calc_tin(pwm_id, period);
-	timer_rate_hz = tin_rate;
 
 	tin_ns = NS_IN_HZ / tin_rate;
 	tcnt = period_ns / tin_ns;