ARM: mxs: Let mmc0 pin detect be generic

Instead of assigning SSP1_DETECT inside mmc0_4bit_pins_a, let the board dts
handle this setup.

Not every board will use MX23_PAD_SSP1_DETECT as SSP1 functionality.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>

arch/arm/boot/dts/imx23-evk.dts

@@ -48,6 +48,7 @@
 						0x1123 /* MX23_PAD_LCD_RESET__GPIO_1_18 */
 						0x11d3 /* MX23_PAD_PWM3__GPIO_1_29 */
 						0x11e3 /* MX23_PAD_PWM4__GPIO_1_30 */
+						0x2010 /* MX23_PAD_SSP1_DETECT__SSP1_DETECT */
 					>;
 					fsl,drive-strength = <0>;
 					fsl,voltage = <1>;

arch/arm/boot/dts/imx23.dtsi

@@ -194,7 +194,6 @@
 						0x2040 /* MX23_PAD_SSP1_DATA2__SSP1_DATA2 */
 						0x2050 /* MX23_PAD_SSP1_DATA3__SSP1_DATA3 */
 						0x2000 /* MX23_PAD_SSP1_CMD__SSP1_CMD */
-						0x2010 /* MX23_PAD_SSP1_DETECT__SSP1_DETECT */
 						0x2060 /* MX23_PAD_SSP1_SCK__SSP1_SCK */
 					>;
 					fsl,drive-strength = <1>;