imx8m_evk: Remove unneeded earlycon string

Passing earlycon string in the command line may be
useful during bring up, but not after such phase.

Remove the earlycon string to align with the other i.MX SoCs
command lines.

Signed-off-by: Fabio Estevam <festevam@gmail.com>
diff --git a/include/configs/imx8mq_evk.h b/include/configs/imx8mq_evk.h
index b29989d..5d9ef70 100644
--- a/include/configs/imx8mq_evk.h
+++ b/include/configs/imx8mq_evk.h
@@ -103,7 +103,7 @@
 	CONFIG_MFG_ENV_SETTINGS \
 	"script=boot.scr\0" \
 	"image=Image\0" \
-	"console=ttymxc0,115200 earlycon=ec_imx6q,0x30860000,115200\0" \
+	"console=ttymxc0,115200\0" \
 	"fdt_addr=0x43000000\0"			\
 	"fdt_high=0xffffffffffffffff\0"		\
 	"boot_fdt=try\0" \