package/rauc: select fw_printenv for uboot based systems

When operating on a uboot based system, rauc interacts with
the bootloader environment using fw_printenv and fw_setenv [1].

These commands should therefore be present on the target if
the system being built uses uboot.

[1] See:
https://github.com/rauc/rauc/blob/v1.2/src/bootchooser.c#L21-L22
https://github.com/rauc/rauc/blob/v1.2/src/bootchooser.c#L644-L645

Signed-off-by: Titouan Christophe <titouan.christophe@railnova.eu>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit ccf67ebe3b93bf659e64e4e933f2e0bac148a141)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/rauc/Config.in

@@ -7,6 +7,8 @@ config BR2_PACKAGE_RAUC
 	select BR2_PACKAGE_OPENSSL
 	select BR2_PACKAGE_DBUS # run-time dependency
 	select BR2_PACKAGE_SQUASHFS # run-time dependency
+	select BR2_PACKAGE_UBOOT_TOOLS if BR2_TARGET_UBOOT # run-time dependency
+	select BR2_PACKAGE_UBOOT_TOOLS_FWPRINTENV if BR2_TARGET_UBOOT
 	help
 	  RAUC is the Robust Auto-Update Controller developed by
 	  Pengutronix. It supports updating embedded Linux