stm32mp1: board: check the boot-source to disable bootdelay

Allows to avoid to wait 2 second in U-Boot before to
start STM32CubeProgrammer command.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
diff --git a/board/st/stm32mp1/stm32mp1.c b/board/st/stm32mp1/stm32mp1.c
index b3bff5f..1be1160 100644
--- a/board/st/stm32mp1/stm32mp1.c
+++ b/board/st/stm32mp1/stm32mp1.c
@@ -624,6 +624,7 @@
 
 int board_late_init(void)
 {
+	char *boot_device;
 #ifdef CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
 	const void *fdt_compat;
 	int fdt_compat_len;
@@ -660,6 +661,11 @@
 	/* for DK1/DK2 boards */
 	board_check_usb_power();
 
+	/* Check the boot-source to disable bootdelay */
+	boot_device = env_get("boot_device");
+	if (!strcmp(boot_device, "serial") || !strcmp(boot_device, "usb"))
+		env_set("bootdelay", "0");
+
 	return 0;
 }