3rdparty/arm-trusted-firmware: Update submodule to upstream master

Updating from commit id 37366af8d:
2023-07-28 17:04:54 +0200 - (Merge "fix(cpus): fix minor issue seen with a9 cpu" into integration)

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

This brings in 225 new commits.

Change-Id: I97147fbec5c0a91daab67524027f57962f61d0a1
Signed-off-by: Felix Singer <felixsinger@posteo.net>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/78886
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
diff --git a/3rdparty/arm-trusted-firmware b/3rdparty/arm-trusted-firmware
index 37366af..88b2d81 160000
--- a/3rdparty/arm-trusted-firmware
+++ b/3rdparty/arm-trusted-firmware
@@ -1 +1 @@
-Subproject commit 37366af8d4b33213abf7acb3b0523d9a3510fb52
+Subproject commit 88b2d81345dfd84902aae586a743d00ac5df2f48