configs/qemu_arm_vexpress_tz_defconfig: optee-os needs dtc compiler

optee-os 3.17.0 need host-dtc package to compile the devicetree
added by the commit [1].

[1] https://github.com/OP-TEE/optee_os/commit/3e03eb38ae68be06f43432d8034b69b7b3bd7ff6

Fixes:
https://gitlab.com/kubu93/buildroot/-/jobs/2510255578

Signed-off-by: Romain Naour <romain.naour@gmail.com>
Cc: Etienne Carriere <etienne.carriere@linaro.org>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

configs/qemu_arm_vexpress_tz_defconfig

@@ -38,6 +38,7 @@ BR2_TARGET_ARM_TRUSTED_FIRMWARE_ADDITIONAL_VARIABLES="BL32_RAM_LOCATION=tdram"
 
 # OP-TEE components
 BR2_TARGET_OPTEE_OS=y
+BR2_TARGET_OPTEE_OS_NEEDS_DTC=y
 BR2_TARGET_OPTEE_OS_PLATFORM="vexpress-qemu_virt"
 BR2_PACKAGE_OPTEE_BENCHMARK=y
 BR2_PACKAGE_OPTEE_EXAMPLES=y