ppc4xx: Fix i2c divisor calcularion for PPC4xx

This patch fixes changes the i2c_init(...) function to use the function
get_OPB_freq() rather than calculating the OPB speed by
sysInfo.freqPLB/sysInfo.pllOpbDiv. The get_OPB_freq() function is
specific per processor. The prior method was not and so was calculating
the wrong speed for some PPC4xx processors.

Signed-off-by: Jeffrey Mann <mannj@embeddedplanet.com>
Signed-off-by: Stefan Roese <sr@denx.de>

cpu/ppc4xx/i2c.c

@@ -91,7 +91,6 @@ static void _i2c_bus_reset(void)
 
 void i2c_init(int speed, int slaveadd)
 {
-	sys_info_t sysInfo;
 	unsigned long freqOPB;
 	int val, divisor;
 	int bus;
@@ -124,8 +123,7 @@ void i2c_init(int speed, int slaveadd)
 
 		/* Clock divide Register */
 		/* get OPB frequency */
-		get_sys_info(&sysInfo);
-		freqOPB = sysInfo.freqPLB / sysInfo.pllOpbDiv;
+		freqOPB = get_OPB_freq();
 		/* set divisor according to freqOPB */
 		divisor = (freqOPB - 1) / 10000000;
 		if (divisor == 0)