pitx-imx8m: fix boot_scripts environment variable

- Move 'boot_scripts' definition _behind_ the BOOTENV, otherwise
  this will overwrite 'boot_scripts' variable with its own definition.
Signed-off-by: Thomas Schaefer <thomas.schaefer@kontron.com>

include/configs/pitx-imx8m.h

@@ -161,10 +161,10 @@
 	"fdtfile=pitx-imx8m_hdmi.dtb\0"						\
 	"initrd_addr=0x43800000\0"						\
 	"initrd_high=0xffffffffffffffff\0" 					\
-	"boot_scripts=boot.scr.uimg boot.scr update_pitx/update.scr\0"		\
 	"video_off=yes\0"							\
 	DISTROBOOT_ENV_SETTINGS							\
-	BOOTENV
+	BOOTENV									\
+	"boot_scripts=boot.scr.uimg boot.scr update_pitx/update.scr\0"