hikey: clean sram before mcu used

Clean cache to flush parameters into SRAM before MCU using them.
Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>

plat/hisilicon/hikey/hikey_bl2_setup.c

@@ -304,15 +304,13 @@ void bl2_platform_setup(void)
 	hikey_gpio_init();
 	hikey_pmussi_init();
 	hikey_hi6553_init();
+	/* Clear SRAM since it'll be used by MCU right now. */
+	memset((void *)SRAM_BASE, 0, SRAM_SIZE);
 
 	dsb();
 	hikey_ddr_init(DDR_FREQ_800M);
 	hikey_security_setup();
 
-	/* Clear SRAM since it'll be used by MCU right now. */
-	memset((void *)SRAM_BASE, 0, SRAM_SIZE);
-	clean_dcache_range(SRAM_BASE, SRAM_SIZE);
-
 	hikey_boardid_init();
 	init_acpu_dvfs();
 	hikey_rtc_init();
@@ -321,6 +319,9 @@ void bl2_platform_setup(void)
 
 	hikey_mmc_pll_init();
 
+	/* Clean SRAM before MCU used */
+	clean_dcache_range(SRAM_BASE, SRAM_SIZE);
+
 	reset_dwmmc_clk();
 	memset(&params, 0, sizeof(dw_mmc_params_t));
 	params.reg_base = DWMMC0_BASE;