configs: nitrogen6x: Add DM_SPI/DM_SPI_FLASH support

Add CONFIG_DM_SPI/CONFIG_DM_SPI_FLASH to all defconfigs whose board is
    nitrogen6x.

    mx6qsabrelite_defconfig
    nitrogen6dl2g_defconfig
    nitrogen6dl_defconfig
    nitrogen6q2g_defconfig
    nitrogen6q_defconfig
    nitrogen6s1g_defconfig

Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
diff --git a/configs/nitrogen6q2g_defconfig b/configs/nitrogen6q2g_defconfig
index 351bbeb..2c4def6 100644
--- a/configs/nitrogen6q2g_defconfig
+++ b/configs/nitrogen6q2g_defconfig
@@ -47,6 +47,7 @@
 CONFIG_FSL_USDHC=y
 CONFIG_DM_GPIO=y
 CONFIG_DM_MMC=y
+CONFIG_DM_SPI_FLASH=y
 CONFIG_SPI_FLASH=y
 CONFIG_SF_DEFAULT_MODE=0
 CONFIG_SF_DEFAULT_SPEED=25000000
@@ -56,6 +57,7 @@
 CONFIG_PHY_MICREL_KSZ90X1=y
 CONFIG_MII=y
 CONFIG_SPI=y
+CONFIG_DM_SPI=y
 CONFIG_MXC_SPI=y
 CONFIG_USB=y
 CONFIG_DM_USB=y