Merge patch series "Add support for DT overlays handoff"

Raymond Mao <raymond.mao@linaro.org> says:

The series include refactoring on bloblist and fdtdec to support handoff
of multiple DT overlays and applying them into the DT base during setup.
All changes are aligned to the spec update for supporting DT overlay
handoff[1].

Notes for testing:

Currently DT overlay is not yet enabled in TF-A, but with the test
patches I provided for TF-A and OP-TEE build, importing a DT overlay
blob file from QEMU to TF-A reserved memory is supported.
Follow below instructions to build and run for test:
$ repo init -u https://github.com/OP-TEE/manifest.git -m qemu_v8.xml
Replace your local qemu_v8.xml with [2], which contains all necessary
changes in both TF-A and OP-TEE build.
$ repo sync
$ cd build
$ make toolchains
$ make ARM_FIRMWARE_HANDOFF=y all
Copy and rename your DT overlay blob as 'qemu_v8.dtb' into out/bin
$ make ARM_FIRMWARE_HANDOFF=y run-only

[1] Add Transfer Entry for Devicetree Overlay
https://github.com/FirmwareHandoff/firmware_handoff/pull/74

[2] https://github.com/raymo200915/optee_manifest/blob/dt_overlay_handoff/qemu_v8.xml

Link: https://lore.kernel.org/r/20250718141621.3147633-1-raymond.mao@linaro.org

diff --cc common/bloblist.c
Simple merge

diff --cc configs/qemu_arm64_defconfig
Simple merge

diff --cc lib/fdtdec.c
Simple merge