[M] Change in coreboot[main]: mb/google/fatcat: Introduce phased pre-memory GPIO configuration

[Subrata Banik (Code Review)]

Attention is currently required from: Jayvik Desai, Kapil Porwal, Pranava Y N.

Hello Jayvik Desai, Kapil Porwal, Pranava Y N,

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

https://review.coreboot.org/c/coreboot/+/87191?usp=email

to look at the new patch set (#2).

Change subject: mb/google/fatcat: Introduce phased pre-memory GPIO configuration
......................................................................

mb/google/fatcat: Introduce phased pre-memory GPIO configuration

This commit restructures the `fw_config_configure_pre_mem_gpio`
function for fatcat variant to perform GPIO configuration in two
distinct phases:

- Phase 1: This phase configures essential GPIOs related to WWAN
  and storage power sequencing, as well as fingerprint presence
  detection. This aligns with the initial power-up requirements of
  these critical components.

- Phase 2: This phase handles GPIO configurations for various
  peripherals like storage type, audio codec, WiFi, cellular interface
  (post initial power sequence), SD card slot, touchpad, touchscreen,
  ISH, PEG/x4 slot wake disable, and fingerprint enable/disable based
  on FW_CONFIG probes.

This phased approach aims to:

- Improve power sequencing: By configuring GPIOs in a specific order,
  we ensure that power rails for different IP blocks are enabled with
  the necessary delays, avoiding potential power-up issues.
- Optimize boot time: Moving more GPIO configurations to the pre-memory
  stage allows these configurations to happen in parallel with FSP-S
  execution. This reduces the amount of GPIO configuration needed
  during the ramstage, potentially saving around 20ms during device
  setup and PCIe bus scanning.

TEST=Able to save ~20ms of the device setup time while booting
google/fatcat.

w/o patch:

```
  70:device setup done                                 1,339,599 (95,023)
```

w/ patch:

```
  70:device setup done                                 1,319,613 (72,381)
```

Change-Id: I9c2e58ae012cad06f8e498c75745efaa9bad4a25
Signed-off-by: Subrata Banik 
---
M src/mainboard/google/fatcat/variants/fatcat/fw_config.c
1 file changed, 105 insertions(+), 92 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/91/87191/2