configs/warp7: select BR2_TARGET_UBOOT_NEEDS_OPENSSL

Select BR2_TARGET_UBOOT_NEEDS_OPENSSL to fix the following build
error:

include/image.h:1178:12: fatal error: openssl/evp.h: No such file or directory
 1178 | #  include <openssl/evp.h>
      |            ^~~~~~~~~~~~~~~

Fixes:
- https://gitlab.com/buildroot.org/buildroot/-/jobs/1915006500
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

configs/warp7_defconfig

@@ -27,6 +27,7 @@ BR2_TARGET_UBOOT_BOARDNAME="warp7"
 BR2_TARGET_UBOOT_CUSTOM_VERSION=y
 BR2_TARGET_UBOOT_CUSTOM_VERSION_VALUE="2021.10"
 BR2_TARGET_UBOOT_FORMAT_DTB_IMX=y
+BR2_TARGET_UBOOT_NEEDS_OPENSSL=y
 
 # wifi firmware for brcm43430
 BR2_PACKAGE_LINUX_FIRMWARE=y