imx: mx6ul configure the PMIC_STBY_REQ pin as open drain

Configure the PMIC_STBY_REQ pin as open drain 100K according
to the design team's requirement for the PMIC_STBY_REQ pin
for i.MX 6UltraLite TO1.0.

Signed-off-by: Peng Fan <van.freenix@gmail.com>
Cc: Stefano Babic <sbabic@denx.de>

arch/arm/cpu/armv7/mx6/soc.c

@@ -341,7 +341,17 @@ int arch_cpu_init(void)
 			set_ahb_rate(132000000);
 	}
 
-		/* Set perclk to source from OSC 24MHz */
+	if (IS_ENABLED(CONFIG_MX6UL) && is_soc_rev(CHIP_REV_1_0) == 0) {
+		/*
+		 * According to the design team's requirement on i.MX6UL,
+		 * the PMIC_STBY_REQ PAD should be configured as open
+		 * drain 100K (0x0000b8a0).
+		 * Only exists on TO1.0
+		 */
+		writel(0x0000b8a0, IOMUXC_BASE_ADDR + 0x29c);
+	}
+
+	/* Set perclk to source from OSC 24MHz */
 #if defined(CONFIG_MX6SL)
 	set_preclk_from_osc();
 #endif