ARM: dts: colibri-imx6ull: Change drive strength for usdhc2

The current setting reflects about 86 Ohms of source-impedance
on the SDIO signals where the WiFi board is hooked up. PCB traces are
routed with 50 Ohms impedance and there are no serial resistors on
those traces.

This commit changes the source-impedance to 52 Ohms to better match our
hardware design.

The impedances given in this commit message refer to 3.3V operation.
Signed-off-by: Philippe Schenker <philippe.schenker@toradex.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/imx6ull-colibri.dtsi

@@ -522,12 +522,12 @@ MX6UL_PAD_SD1_DATA3__USDHC1_DATA3	0x170b9
 
 	pinctrl_usdhc2: usdhc2-grp {
 		fsl,pins = <
-			MX6UL_PAD_CSI_DATA00__USDHC2_DATA0	0x17059
-			MX6UL_PAD_CSI_DATA01__USDHC2_DATA1	0x17059
-			MX6UL_PAD_CSI_DATA02__USDHC2_DATA2	0x17059
-			MX6UL_PAD_CSI_DATA03__USDHC2_DATA3	0x17059
-			MX6UL_PAD_CSI_HSYNC__USDHC2_CMD		0x17059
-			MX6UL_PAD_CSI_VSYNC__USDHC2_CLK		0x17059
+			MX6UL_PAD_CSI_DATA00__USDHC2_DATA0	0x17069
+			MX6UL_PAD_CSI_DATA01__USDHC2_DATA1	0x17069
+			MX6UL_PAD_CSI_DATA02__USDHC2_DATA2	0x17069
+			MX6UL_PAD_CSI_DATA03__USDHC2_DATA3	0x17069
+			MX6UL_PAD_CSI_HSYNC__USDHC2_CMD		0x17069
+			MX6UL_PAD_CSI_VSYNC__USDHC2_CLK		0x17069
 
 			MX6UL_PAD_GPIO1_IO03__OSC32K_32K_OUT	0x10
 		>;