boot/uboot: add BR2_TARGET_UBOOT_NEEDS_XXD option

A host dependency to xxd is required if the U-Boot board
configuration has CONFIG_USE_DEFAULT_ENV_FILE enabled. So
introduce a new BR U-Boot config option BR2_TARGET_UBOOT_NEEDS_XXD
to solve this problem. xxd is provided by host-vim.

Signed-off-by: Jerry Kooyman <jerry.kooyman@entrust.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

boot/uboot/Config.in

@@ -198,6 +198,14 @@ config BR2_TARGET_UBOOT_NEEDS_UTIL_LINUX
 	  This is typically the case when the board configuration
 	  has CONFIG_TOOLS_MKEFICAPSULE enabled.
 
+config BR2_TARGET_UBOOT_NEEDS_XXD
+	bool "U-Boot needs xxd"
+	help
+	  Select this option if your U-Boot board configuration
+	  requires xxd to be available on the host. This is
+	  typically the case when the board configuration has
+	  CONFIG_USE_DEFAULT_ENV_FILE enabled.
+
 config BR2_TARGET_UBOOT_NEEDS_ATF_BL31
 	bool "U-Boot needs ATF BL31"
 	depends on BR2_TARGET_ARM_TRUSTED_FIRMWARE

boot/uboot/uboot.mk

@@ -239,6 +239,10 @@ ifeq ($(BR2_TARGET_UBOOT_NEEDS_UTIL_LINUX),y)
 UBOOT_DEPENDENCIES += host-util-linux
 endif
 
+ifeq ($(BR2_TARGET_UBOOT_NEEDS_XXD),y)
+UBOOT_DEPENDENCIES += host-vim
+endif
+
 # prior to u-boot 2013.10 the license info was in COPYING. Copy it so
 # legal-info finds it
 define UBOOT_COPY_OLD_LICENSE_FILE