binman's split-elf operation records one FIT image node per ELF
segment, all with os = "tee", and only the segment containing the ELF
entry point carries an entry property. Since fdt_add_subnode() inserts
new subnodes in front of existing ones, the /fit-images nodes end up in
reverse recording order, so spl_fit_images_find() would return the
*last* TEE segment and its load address was passed to BL31 as the BL32
entry point.
On RK3588 with an OP-TEE tee.elf consisting of two PT_LOAD segments
this made BL31 (SPD=opteed) ERET into OP-TEE's data segment at
0x30200000 instead of the entry point at 0x30000000, hanging the boot
right after 'BL31: Initializing BL32'.
Prefer the FIT image node which provides an entry property and only
fall back to the first matching node when none of them has one.
Signed-off-by: Daniel Golle <daniel@makrotopia.org>