support/testing: fix Marvell ATF source code

The version of the ARM Trusted Firmware from Marvell was a Git branch,
not a Git commit, leading to unreproducible results. So let's use a
Git commit instead, which is the latest available from the branch that
was previously used.

More specifically, this branch has recently seen a fix that is needed
for ATF to build properly with recent gcc versions:

  https://github.com/MarvellEmbeddedProcessors/atf-marvell/commit/c96ec59f8b819123a06e1839ab5578030cf263b0

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

support/testing/tests/boot/test_atf.py

@@ -63,7 +63,7 @@ class TestATFMarvell(infra.basetest.BRTest):
         BR2_TARGET_ARM_TRUSTED_FIRMWARE=y
         BR2_TARGET_ARM_TRUSTED_FIRMWARE_CUSTOM_GIT=y
         BR2_TARGET_ARM_TRUSTED_FIRMWARE_CUSTOM_REPO_URL="https://github.com/MarvellEmbeddedProcessors/atf-marvell.git"
-        BR2_TARGET_ARM_TRUSTED_FIRMWARE_CUSTOM_REPO_VERSION="atf-v1.3-armada-17.10"
+        BR2_TARGET_ARM_TRUSTED_FIRMWARE_CUSTOM_REPO_VERSION="43965481990fd92e9666cf9371a8cf478055ec7c"
         BR2_TARGET_ARM_TRUSTED_FIRMWARE_PLATFORM="a80x0_mcbin"
         BR2_TARGET_ARM_TRUSTED_FIRMWARE_FIP=y
         BR2_TARGET_ARM_TRUSTED_FIRMWARE_UBOOT_AS_BL33=y