pico-imx7d: Allow default fdtfile to be overridden by defconfig

This allow the addition of extra default configurations for each
baseboard, removing the boot menu when user boots for the first time.

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>

configs/pico-imx7d_defconfig

@@ -14,6 +14,7 @@ CONFIG_IMX_RDC=y
 CONFIG_DISTRO_DEFAULTS=y
 CONFIG_SYS_EXTRA_OPTIONS="IMX_CONFIG=arch/arm/mach-imx/spl_sd.cfg"
 CONFIG_BOOTCOMMAND="run findfdt; run finduuid; run distro_bootcmd"
+CONFIG_DEFAULT_FDT_FILE="ask"
 CONFIG_SPL_I2C_SUPPORT=y
 CONFIG_SPL_USB_HOST_SUPPORT=y
 CONFIG_SPL_USB_GADGET_SUPPORT=y

include/configs/pico-imx7d.h

@@ -65,7 +65,7 @@
 	"console=ttymxc4\0" \
 	"fdt_high=0xffffffff\0" \
 	"initrd_high=0xffffffff\0" \
-	"fdtfile=ask\0" \
+	"fdtfile=" CONFIG_DEFAULT_FDT_FILE "\0" \
 	BOOTMENU_ENV \
 	"fdt_addr=0x83000000\0" \
 	"fdt_addr_r=0x83000000\0" \