armv7: ls102xa: Enable I-Cache to speed up the boot time

Enable the I-Cache to speed up the boot time, especailly for the NOR
boot, currently it takes about 15 seconds from power up to the U-Boot
prompt, and with the I-Cache enabled it only takes around 2.5 seconds.
Signed-off-by: NHou Zhiqiang <Zhiqiang.Hou@nxp.com>
Reviewed-by: NPriyanka Jain <priyanka.jain@nxp.com>

arch/arm/cpu/armv7/ls102xa/cpu.c

@@ -316,6 +316,8 @@ int arch_cpu_init(void)
 	struct ccsr_scfg *scfg = (void *)CONFIG_SYS_FSL_SCFG_ADDR;
 	u32 state;
 
+	icache_enable();
+
 	/*
 	 * The RCPM FSM state may not be reset after power-on.
 	 * So, reset them.