[L] Change in coreboot[main]: mb/lattepanda: Add support for LattePanda Mu

[KunYi Chen (Code Review)]

Attention is currently required from: Felix Held, KunYi Chen, Martin L Roth, Nicholas Chin, Nicholas Sudsgaard, Paul Menzel.

Hello Felix Held, Nicholas Chin, Nicholas Sudsgaard, build bot (Jenkins),

I'd like you to reexamine a change. Please visit

https://review.coreboot.org/c/coreboot/+/83719?usp=email

to look at the new patch set (#11).

The following approvals got outdated and were removed:
Code-Review+1 by Nicholas Sudsgaard, Verified+1 by build bot (Jenkins)

Change subject: mb/lattepanda: Add support for LattePanda Mu
......................................................................

mb/lattepanda: Add support for LattePanda Mu

Add initial support for the LattePanda Mu board, which features:
  - Intel Alder Lake-N N100 processor
  - 8GB LPDDR5 memory
  - 64GB eMMC storage
  - SO-DIMM 260-pin connector for function expansion

This commit includes:
  - Basic board configuration
  - Memory initialization
  - Essential I/O setup

Testing with Lite carrier board
  - Booting into installed Windows 11: Passed
  - USB 3.0/2.0: Working
  - HDMI output: Working
  - Realtek Ethernet: Working

- S3 sleep mode: Failed
  - Power on after shutdown: Failed (requires power removal)
  - Installing Ubuntu 22.04: Failed
  - UART of SuperIO in OS: Missing
  - Environment Controller: Not supported
  - M.2/M Key: Not working (booting failed with SSD 512GB installed)

Change-Id: I79696bdd837a221860b32f54629212c3346dca66
Signed-off-by: KunYi Chen 
---
A configs/config.lattepanda_mu
A src/mainboard/lattepanda/Kconfig
A src/mainboard/lattepanda/Kconfig.name
A src/mainboard/lattepanda/mu/Kconfig
A src/mainboard/lattepanda/mu/Kconfig.name
A src/mainboard/lattepanda/mu/Makefile.mk
A src/mainboard/lattepanda/mu/board_info.txt
A src/mainboard/lattepanda/mu/bootblock.c
A src/mainboard/lattepanda/mu/data.vbt
A src/mainboard/lattepanda/mu/devicetree.cb
A src/mainboard/lattepanda/mu/dsdt.asl
A src/mainboard/lattepanda/mu/gpio.c
A src/mainboard/lattepanda/mu/include/baseboard/gpio.h
A src/mainboard/lattepanda/mu/include/baseboard/variants.h
A src/mainboard/lattepanda/mu/mainboard.c
A src/mainboard/lattepanda/mu/memory.c
A src/mainboard/lattepanda/mu/ramstage.c
A src/mainboard/lattepanda/mu/romstage_fsp_params.c
A src/mainboard/lattepanda/mu/spd/Makefile.mk
A src/mainboard/lattepanda/mu/spd/mu_lp5_16gb.spd.hex
A src/mainboard/lattepanda/mu/spd/mu_lp5_8gb.spd.hex
21 files changed, 696 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/19/83719/11