support spidev in user space

add CONFIG_SPI_SPIDEV=y, so can access /dev/spidevB.C in user space.

Change-Id: I71194db443a0cb4933a7b893fd504a275fb5483e
Signed-off-by: fang hui <hui.fang@freescale.com>
diff --git a/arch/arm/configs/imx_v7_android_defconfig b/arch/arm/configs/imx_v7_android_defconfig
index 3f42ff0..20f69c6 100644
--- a/arch/arm/configs/imx_v7_android_defconfig
+++ b/arch/arm/configs/imx_v7_android_defconfig
@@ -328,6 +328,7 @@
 CONFIG_SPI=y
 CONFIG_SPI_GPIO=y
 CONFIG_SPI_IMX=y
+CONFIG_SPI_SPIDEV=y
 CONFIG_GPIO_SYSFS=y
 CONFIG_GPIO_MAX732X=y
 CONFIG_GPIO_74X164=y