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: NFabio Estevam <festevam@gmail.com>

include/configs/imx8mm_evk.h

@@ -39,7 +39,7 @@
 #define CONFIG_EXTRA_ENV_SETTINGS		\
 	"script=boot.scr\0" \
 	"image=Image.itb\0" \
-	"console=ttymxc1,115200 earlycon=ec_imx6q,0x30890000,115200\0" \
+	"console=ttymxc1,115200\0" \
 	"fdt_addr=0x43000000\0"			\
 	"fdt_high=0xffffffffffffffff\0"		\
 	"boot_fit=try\0" \

include/configs/imx8mn_evk.h

@@ -42,7 +42,7 @@
 #define CONFIG_EXTRA_ENV_SETTINGS		\
 	"script=boot.scr\0" \
 	"image=Image.itb\0" \
-	"console=ttymxc1,115200 earlycon=ec_imx6q,0x30890000,115200\0" \
+	"console=ttymxc1,115200\0" \
 	"fdt_addr=0x43000000\0"			\
 	"fdt_high=0xffffffffffffffff\0"		\
 	"boot_fit=try\0" \

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" \