mx6slevk_spl: Remove SPL entry from CONFIG_SYS_EXTRA_OPTIONS

SPL is already selected via CONFIG_SPL=y, so there is no need
to pass it inside CONFIG_SYS_EXTRA_OPTIONS.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
diff --git a/configs/mx6slevk_spl_defconfig b/configs/mx6slevk_spl_defconfig
index 1fd86fc..ad15e7a 100644
--- a/configs/mx6slevk_spl_defconfig
+++ b/configs/mx6slevk_spl_defconfig
@@ -9,7 +9,7 @@
 CONFIG_SPL_LIBDISK_SUPPORT=y
 CONFIG_SPL_WATCHDOG_SUPPORT=y
 # CONFIG_CMD_BMODE is not set
-CONFIG_SYS_EXTRA_OPTIONS="IMX_CONFIG=arch/arm/imx-common/spl_sd.cfg,SPL,MX6SL,SYS_I2C"
+CONFIG_SYS_EXTRA_OPTIONS="IMX_CONFIG=arch/arm/imx-common/spl_sd.cfg,MX6SL,SYS_I2C"
 CONFIG_BOOTDELAY=3
 CONFIG_BOARD_EARLY_INIT_F=y
 CONFIG_SPL=y