[M] Change in coreboot[main]: soc/mediatek: Add common implmentation to configure display

[Yidi Lin (Code Review)]

Attention is currently required from: Hung-Te Lin, Paul Menzel, Yu-Ping Wu.

Yidi Lin has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/79776?usp=email )

Change subject: soc/mediatek: Add common implmentation to configure display
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Patch Set 2:

(2 comments)

File src/mainboard/google/geralt/panel.h:

https://review.coreboot.org/c/coreboot/+/79776/comment/24a55f31_11798fe7 :
PS1, Line 23: struct panel_description *get_active_panel(void);
> I think the declaration should be kept here, because the implementation is in geralt/panel.c.

If so, do you suggest passing `struct panel_description panl` to `mtk_display_init` (configure_display) instead of calling `get_active_panel()` inside `mtk_display_init` ?

File src/soc/mediatek/common/display.c:

https://review.coreboot.org/c/coreboot/+/79776/comment/809fd80e_f8bf934c :
PS1, Line 42: 		if (panel->get_edid && panel->get_edid(panel) < 0)
> So, this is only for eDP bridges, right? For consistency, I think `get_mipi_cmd_from_cbfs()`, which  […]

Sounds good.