Update arm-trusted-firmware submodule to upstream master

Updating from commit id 88b2d8134:
2023-09-06 11:26:32 +0200 - (Merge "fix(scmi): add parameter for plat_scmi_clock_rates_array" into integration)

to commit id e7486343d:
2023-11-28 22:48:16 +0100 - (Merge changes from topic "xlnx_fitimage_check" into integration)

This brings in 451 new commits.

Change-Id: I75a89c6f0d60ccccd8ff42954416666dabef717f
Signed-off-by: Yidi Lin <yidilin@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/79333
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Yu-Ping Wu <yupingso@google.com>
diff --git a/3rdparty/arm-trusted-firmware b/3rdparty/arm-trusted-firmware
index 88b2d81..e748634 160000
--- a/3rdparty/arm-trusted-firmware
+++ b/3rdparty/arm-trusted-firmware
@@ -1 +1 @@
-Subproject commit 88b2d81345dfd84902aae586a743d00ac5df2f48
+Subproject commit e7486343d46a0d60047233adfd8a64436bbac1fd