Update the vendored FSBL from Sophgo sg200x-dev commit
426d1e7eccce84b34169e5f21de7d6e7da1804a1 to
5a80c127cf614dea7f534d5b5352886a1c720d37, incorporating 24 upstream
commits. Keep the local plat/sg200x symlink to cv181x.
Import the upstream DDR, clock, storage and boot-image changes together
with their platform support, prebuilt firmware and licensing files.
All 935 upstream files match the target revision.
Validation on LicheeRV Nano (SG2002/C906, SD, DDR3-1866 x16):
- Cross-build BL2 with the existing Xuantie GCC 10.2.0 toolchain.
- Repack FIP while preserving the installed OpenSBI and U-Boot byte
for byte; verify headers, payload checksums, entry addresses and LZMA.
- Software reboot and power-cycle boot succeed; memtester 16M 1 passes
all 18 checks.
Validation covers the FSBL update with existing later boot stages.
Full firmware builds, A53 and video/HID acceptance are not covered.
