mb/google/geralt: Configure firmware display for eDP panel

mb/google/geralt: Configure firmware display for eDP panel

Add eDP panel power-on sequences and initialize the display in the
ramstage.

eDP panel in MT8188 EVB: "IVO R140NWF5 RH".
Panel spec name: R140NWF5 RH Product Specification

Firmware display eDP panel logs:
configure_display: Starting display initialization
SINK DPCD version: 0x11
SINK SUPPORT SSC!
Extracted contents:
header:          00 ff ff ff ff ff ff 00
serial number:   26 cf 7d 05 00 00 00 00 00 1e
version:         01 04
basic params:    95 1f 11 78 0a
chroma info:     76 90 94 55 54 90 27 21 50 54
established:     00 00 00
standard:        01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01
descriptor 1:    38 36 80 a0 70 38 20 40 18 30 3c 00 35 ae 10 00 00 19
descriptor 2:    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
descriptor 3:    00 00 00 fe 00 49 6e 66 6f 56 69 73 69 6f 6e 0a 20 20
descriptor 4:    00 00 00 fe 00 52 31 34 30 4e 57 46 35 20 52 48 20 0a
extensions:      00
checksum:        fb
Manufacturer: IVO Model 57d Serial Number 0
Made week 0 of 2020
EDID version: 1.4

BUG=b:244208960
TEST=see firmware display using eDP panel in MT8188 EVB.

Signed-off-by: Bo-Chen Chen <rex-bc.chen@mediatek.com>
Change-Id: I67e0699c976c6f85e69d40d77154420c983b715e
Reviewed-on: https://review.coreboot.org/c/coreboot/+/68490
Reviewed-by: Yidi Lin <yidilin@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Yu-Ping Wu <yupingso@google.com>