pico-imx7d: Add GPT partitioning support

This allow the use of:

> run setup_emmc

inside of the U-Boot prompt to do the partitioning of the disk.

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
diff --git a/include/configs/pico-imx7d.h b/include/configs/pico-imx7d.h
index d27b925..9746caa 100644
--- a/include/configs/pico-imx7d.h
+++ b/include/configs/pico-imx7d.h
@@ -50,6 +50,10 @@
 	"ramdiskaddr=0x83000000\0" \
 	"scriptaddr=" __stringify(CONFIG_LOADADDR) "\0" \
 	"finduuid=part uuid mmc 0:1 uuid\0" \
+	"partitions=" \
+		"uuid_disk=${uuid_gpt_disk};" \
+		"name=rootfs,size=0,uuid=${uuid_gpt_rootfs}\0" \
+	"setup_emmc=mmc dev 0; gpt write mmc 0 $partitions; reset;\0" \
 	BOOTENV
 
 #define BOOT_TARGET_DEVICES(func) \