mx6sabresd: 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>

configs/mx6sabresd_defconfig

@@ -9,7 +9,7 @@ CONFIG_SPL_SERIAL_SUPPORT=y
 CONFIG_SPL_LIBDISK_SUPPORT=y
 CONFIG_SPL_WATCHDOG_SUPPORT=y
 CONFIG_VIDEO=y
-CONFIG_SYS_EXTRA_OPTIONS="IMX_CONFIG=arch/arm/imx-common/spl_sd.cfg,SPL,MX6QDL"
+CONFIG_SYS_EXTRA_OPTIONS="IMX_CONFIG=arch/arm/imx-common/spl_sd.cfg,MX6QDL"
 CONFIG_BOOTDELAY=3
 # CONFIG_CONSOLE_MUX is not set
 CONFIG_SYS_CONSOLE_IS_IN_ENV=y